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Service Function Chaining

OpenDaylight Service Function Chaining (SFC) Overview

OpenDaylight Service Function Chaining (SFC) provides the ability to define an ordered list of network services (e.g. firewalls, load balancers). These services are then “stitched” together in the network to create a service chain. This project provides the infrastructure (chaining logic, APIs) needed for ODL to provision a service chain in the network and an end-user application for defining such chains.

  • ACE - Access Control Entry
  • ACL - Access Control List
  • SCF - Service Classifier Function
  • SF - Service Function
  • SFC - Service Function Chain
  • SFF - Service Function Forwarder
  • SFG - Service Function Group
  • SFP - Service Function Path
  • RSP - Rendered Service Path
  • NSH - Network Service Header

SFC User Interface

Overview

The SFC User interface comes with a Command Line Interface (CLI): it provides several Karaf console commands to show the SFC model (SF, SFFs, etc.) provisioned in the datastore.

SFC Web Interface (SFC-UI)

Architecture

SFC-UI operates purely by using RESTCONF.

SFC-UI integration into ODL

SFC-UI integration into ODL

How to access

  1. Run ODL distribution (run karaf)
  2. In Karaf console execute: feature:install odl-sfc-ui
  3. Visit SFC-UI on: http://<odl_ip_address>:8181/sfc/index.html

SFC Command Line Interface (SFC-CLI)

Overview

The Karaf Container offers a complete Unix-like console that allows managing the container. This console can be extended with custom commands to manage the features deployed on it. This feature will add some basic commands to show the provisioned SFC entities.

How to use it

The SFC-CLI implements commands to show some of the provisioned SFC entities: Service Functions, Service Function Forwarders, Service Function Chains, Service Function Paths, Service Function Classifiers, Service Nodes and Service Function Types:

  • List one/all provisioned Service Functions:

    sfc:sf-list [--name <name>]
    
  • List one/all provisioned Service Function Forwarders:

    sfc:sff-list [--name <name>]
    
  • List one/all provisioned Service Function Chains:

    sfc:sfc-list [--name <name>]
    
  • List one/all provisioned Service Function Paths:

    sfc:sfp-list [--name <name>]
    
  • List one/all provisioned Service Function Classifiers:

    sfc:sc-list [--name <name>]
    
  • List one/all provisioned Service Nodes:

    sfc:sn-list [--name <name>]
    
  • List one/all provisioned Service Function Types:

    sfc:sft-list [--name <name>]
    

SFC Southbound REST Plug-in

Overview

The Southbound REST Plug-in is used to send configuration from datastore down to network devices supporting a REST API (i.e. they have a configured REST URI). It supports POST/PUT/DELETE operations, which are triggered accordingly by changes in the SFC data stores.

  • Access Control List (ACL)
  • Service Classifier Function (SCF)
  • Service Function (SF)
  • Service Function Group (SFG)
  • Service Function Schedule Type (SFST)
  • Service Function Forwarder (SFF)
  • Rendered Service Path (RSP)

Southbound REST Plug-in Architecture

From the user perspective, the REST plug-in is another SFC Southbound plug-in used to communicate with network devices.

Southbound REST Plug-in integration into ODL

Southbound REST Plug-in integration into ODL

Configuring Southbound REST Plugin

  1. Run ODL distribution (run karaf)
  2. In Karaf console execute: feature:install odl-sfc-sb-rest
  3. Configure REST URIs for SF/SFF through SFC User Interface or RESTCONF (required configuration steps can be found in the tutorial stated bellow)

Tutorial

Comprehensive tutorial on how to use the Southbound REST Plug-in and how to control network devices with it can be found on: https://wiki.opendaylight.org/view/Service_Function_Chaining:Main#SFC_103

SFC-OVS integration

Overview

SFC-OVS provides integration of SFC with Open vSwitch (OVS) devices. Integration is realized through mapping of SFC objects (like SF, SFF, Classifier, etc.) to OVS objects (like Bridge, TerminationPoint=Port/Interface). The mapping takes care of automatic instantiation (setup) of corresponding object whenever its counterpart is created. For example, when a new SFF is created, the SFC-OVS plug-in will create a new OVS bridge.

The feature is intended for SFC users willing to use Open vSwitch as an underlying network infrastructure for deploying RSPs (Rendered Service Paths).

SFC-OVS Architecture

SFC-OVS uses the OVSDB MD-SAL Southbound API for getting/writing information from/to OVS devices. From the user perspective SFC-OVS acts as a layer between SFC datastore and OVSDB.

SFC-OVS integration into ODL

SFC-OVS integration into ODL

Configuring SFC-OVS

  1. Run ODL distribution (run karaf)
  2. In Karaf console execute: feature:install odl-sfc-ovs
  3. Configure Open vSwitch to use ODL as a manager, using following command: ovs-vsctl set-manager tcp:<odl_ip_address>:6640

Tutorials

Verifying mapping from SFF to OVS

Overview

This tutorial shows the usual workflow during creation of an OVS Bridge with use of the SFC APIs.

Prerequisites
  • Open vSwitch installed (ovs-vsctl command available in shell)
  • SFC-OVS feature configured as stated above
Instructions
  1. In a shell execute: ovs-vsctl set-manager tcp:<odl_ip_address>:6640
  2. Send POST request to URL: http://<odl_ip_address>:8181/restconf/operations/service-function-forwarder-ovs:create-ovs-bridge Use Basic auth with credentials: “admin”, “admin” and set Content-Type: application/json. The content of POST request should be following:
{
    "input":
    {
        "name": "br-test",
        "ovs-node": {
            "ip": "<Open_vSwitch_ip_address>"
        }
    }
}

Open_vSwitch_ip_address is the IP address of the machine where Open vSwitch is installed.

Verification

In a shell execute: ovs-vsctl show. There should be a Bridge with the name br-test and one port/interface called br-test.

Also, the corresponding SFF for this OVS Bridge should be configured, which can be verified through the SFC User Interface or RESTCONF as follows.

  1. Visit the SFC User Interface: http://<odl_ip_address>:8181/sfc/index.html#/sfc/serviceforwarder
  2. Use pure RESTCONF and send a GET request to URL: http://<odl_ip_address>:8181/restconf/config/service-function-forwarder:service-function-forwarders

There should be an SFF, whose name will be ending with br1 and the SFF should contain two DataPlane locators: br1 and testPort.

SFC Classifier User Guide

Overview

Description of classifier can be found in: https://datatracker.ietf.org/doc/draft-ietf-sfc-architecture/

There are two types of classifier:

  1. OpenFlow Classifier
  2. Iptables Classifier

OpenFlow Classifier

OpenFlow Classifier implements the classification criteria based on OpenFlow rules deployed into an OpenFlow switch. An Open vSwitch will take the role of a classifier and performs various encapsulations such NSH, VLAN, MPLS, etc. In the existing implementation, classifier can support NSH encapsulation. Matching information is based on ACL for MAC addresses, ports, protocol, IPv4 and IPv6. Supported protocols are TCP, UDP and SCTP. Actions information in the OF rules, shall be forwarding of the encapsulated packets with specific information related to the RSP.

Classifier Architecture

The OVSDB Southbound interface is used to create an instance of a bridge in a specific location (via IP address). This bridge contains the OpenFlow rules that perform the classification of the packets and react accordingly. The OpenFlow Southbound interface is used to translate the ACL information into OF rules within the Open vSwitch.

Note

in order to create the instance of the bridge that takes the role of a classifier, an “empty” SFF must be created.

Configuring Classifier

  1. An empty SFF must be created in order to host the ACL that contains the classification information.
  2. SFF data plane locator must be configured
  3. Classifier interface must be manually added to SFF bridge.

Administering or Managing Classifier

Classification information is based on MAC addresses, protocol, ports and IP. ACL gathers this information and is assigned to an RSP which turns to be a specific path for a Service Chain.

Iptables Classifier

Classifier manages everything from starting the packet listener to creation (and removal) of appropriate ip(6)tables rules and marking received packets accordingly. Its functionality is available only on Linux as it leverdges NetfilterQueue, which provides access to packets matched by an iptables rule. Classifier requires root privileges to be able to operate.

So far it is capable of processing ACL for MAC addresses, ports, IPv4 and IPv6. Supported protocols are TCP and UDP.

Classifier Architecture

Python code located in the project repository sfc-py/common/classifier.py.

Note

classifier assumes that Rendered Service Path (RSP) already exists in ODL when an ACL referencing it is obtained

  1. sfc_agent receives an ACL and passes it for processing to the classifier
  2. the RSP (its SFF locator) referenced by ACL is requested from ODL
  3. if the RSP exists in the ODL then ACL based iptables rules for it are applied

After this process is over, every packet successfully matched to an iptables rule (i.e. successfully classified) will be NSH encapsulated and forwarded to a related SFF, which knows how to traverse the RSP.

Rules are created using appropriate iptables command. If the Access Control Entry (ACE) rule is MAC address related both iptables and IPv6 tables rules re issued. If ACE rule is IPv4 address related, only iptables rules are issued, same for IPv6.

Note

iptables raw table contains all created rules

Configuring Classifier

Classfier does’t need any configuration.
Its only requirement is that the second (2) Netfilter Queue is not used by any other process and is avalilable for the classifier.

Administering or Managing Classifier

Classifier runs alongside sfc_agent, therefore the command for starting it locally is:

sudo python3.4 sfc-py/sfc_agent.py --rest --odl-ip-port localhost:8181
--auto-sff-name --nfq-class

SFC OpenFlow Renderer User Guide

Overview

The Service Function Chaining (SFC) OpenFlow Renderer (SFC OF Renderer) implements Service Chaining on OpenFlow switches. It listens for the creation of a Rendered Service Path (RSP) in the operational data store, and once received it programs Service Function Forwarders (SFF) that are hosted on OpenFlow capable switches to forward packets through the service chain. Currently the only tested OpenFlow capable switch is OVS 2.9.

Common acronyms used in the following sections:

  • SF - Service Function
  • SFF - Service Function Forwarder
  • SFC - Service Function Chain
  • SFP - Service Function Path
  • RSP - Rendered Service Path

SFC OpenFlow Renderer Architecture

The SFC OF Renderer is invoked after a RSP is created in the operational data store using an MD-SAL listener called SfcOfRspDataListener. Upon SFC OF Renderer initialization, the SfcOfRspDataListener registers itself to listen for RSP changes. When invoked, the SfcOfRspDataListener processes the RSP and calls the SfcOfFlowProgrammerImpl to create the necessary flows in the Service Function Forwarders configured in the RSP. Refer to the following diagram for more details.

SFC OpenFlow Renderer High Level Architecture

SFC OpenFlow Renderer High Level Architecture

SFC OpenFlow Switch Flow pipeline

The SFC OpenFlow Renderer uses the following tables for its Flow pipeline:

  • Table 0, Classifier
  • Table 1, Transport Ingress
  • Table 2, Path Mapper
  • Table 3, Path Mapper ACL
  • Table 4, Next Hop
  • Table 10, Transport Egress

The OpenFlow Table Pipeline is intended to be generic to work for all of the different encapsulations supported by SFC.

All of the tables are explained in detail in the following section.

The SFFs (SFF1 and SFF2), SFs (SF1), and topology used for the flow tables in the following sections are as described in the following diagram.

SFC OpenFlow Renderer Typical Network Topology

SFC OpenFlow Renderer Typical Network Topology

Classifier Table detailed

It is possible for the SFF to also act as a classifier. This table maps subscriber traffic to RSPs, and is explained in detail in the classifier documentation.

If the SFF is not a classifier, then this table will just have a simple Goto Table 1 flow.

Transport Ingress Table detailed

The Transport Ingress table has an entry per expected tunnel transport type to be received in a particular SFF, as established in the SFC configuration.

Here are two example on SFF1: one where the RSP ingress tunnel is MPLS assuming VLAN is used for the SFF-SF, and the other where the RSP ingress tunnel is either Eth+NSH or just NSH with no ethernet.

Priority Match Action
256 EtherType==0x8847 (MPLS unicast) Goto Table 2
256 EtherType==0x8100 (VLAN) Goto Table 2
250 EtherType==0x894f (Eth+NSH) Goto Table 2
250 PacketType==0x894f (NSH no Eth) Goto Table 2
5 Match Any Drop

Table: Table Transport Ingress

Path Mapper Table detailed

The Path Mapper table has an entry per expected tunnel transport info to be received in a particular SFF, as established in the SFC configuration. The tunnel transport info is used to determine the RSP Path ID, and is stored in the OpenFlow Metadata. This table is not used for NSH, since the RSP Path ID is stored in the NSH header.

For SF nodes that do not support NSH tunneling, the IP header DSCP field is used to store the RSP Path Id. The RSP Path Id is written to the DSCP field in the Transport Egress table for those packets sent to an SF.

Here is an example on SFF1, assuming the following details:

  • VLAN ID 1000 is used for the SFF-SF
  • The RSP Path 1 tunnel uses MPLS label 100 for ingress and 101 for egress
  • The RSP Path 2 (symmetric downlink path) uses MPLS label 101 for ingress and 100 for egress
Priority Match Action
256 MPLS Label==100 RSP Path=1, Pop MPLS, Goto Table 4
256 MPLS Label==101 RSP Path=2, Pop MPLS, Goto Table 4
256 VLAN ID==1000, IP DSCP==1 RSP Path=1, Pop VLAN, Goto Table 4
256 VLAN ID==1000, IP DSCP==2 RSP Path=2, Pop VLAN, Goto Table 4
5 Match Any Goto Table 3

Table: Table Path Mapper

Path Mapper ACL Table detailed

This table is only populated when PacketIn packets are received from the switch for TcpProxy type SFs. These flows are created with an inactivity timer of 60 seconds and will be automatically deleted upon expiration.

Next Hop Table detailed

The Next Hop table uses the RSP Path Id and appropriate packet fields to determine where to send the packet next. For NSH, only the NSP (Network Services Path, RSP ID) and NSI (Network Services Index, next hop) fields from the NSH header are needed to determine the VXLAN tunnel destination IP. For VLAN or MPLS, then the source MAC address is used to determine the destination MAC address.

Here are two examples on SFF1, assuming SFF1 is connected to SFF2. RSP Paths 1 and 2 are symmetric VLAN paths. RSP Paths 3 and 4 are symmetric NSH paths. RSP Path 1 ingress packets come from external to SFC, for which we don’t have the source MAC address (MacSrc).

Priority Match Action
256 RSP Path==1, MacSrc==SF1 MacDst=SFF2, Goto Table 10
256 RSP Path==2, MacSrc==SF1 Goto Table 10
256 RSP Path==2, MacSrc==SFF2 MacDst=SF1, Goto Table 10
246 RSP Path==1 MacDst=SF1, Goto Table 10
550 dl_type=0x894f, nsh_spi=3,nsh_si=255 (NSH, SFF Ingress RSP 3, hop 1) load:0xa000002→ NXM_NX_TUN_IPV4_DST[], Goto Table 10
550 dl_type=0x894f nsh_spi=3,nsh_si=254 (NSH, SFF Ingress from SF, RSP 3, hop 2) load:0xa00000a→ NXM_NX_TUN_IPV4_DST[], Goto Table 10
550 dl_type=0x894f, nsh_spi=4,nsh_si=254 (NSH, SFF1 Ingress from SFF2) load:0xa00000a→ NXM_NX_TUN_IPV4_DST[], Goto Table 10
5 Match Any Drop

Table: Table Next Hop

Transport Egress Table detailed

The Transport Egress table prepares egress tunnel information and sends the packets out.

Here are two examples on SFF1. RSP Paths 1 and 2 are symmetric MPLS paths that use VLAN for the SFF-SF. RSP Paths 3 and 4 are symmetric NSH paths. Since it is assumed that switches used for NSH will only have one VXLAN port, the NSH packets are just sent back where they came from.

Priority Match Action
256 RSP Path==1, MacDst==SF1 Push VLAN ID 1000, Port=SF1
256 RSP Path==1, MacDst==SFF2 Push MPLS Label 101, Port=SFF2
256 RSP Path==2, MacDst==SF1 Push VLAN ID 1000, Port=SF1
246 RSP Path==2 Push MPLS Label 100, Port=Ingress
256 in_port=1,dl_type=0x894f nsh_spi=0x3,nsh_si=255 (NSH, SFF Ingress RSP 3) IN_PORT
256 in_port=1,dl_type=0x894f, nsh_spi=0x3,nsh_si=254 (NSH,SFF Ingress from SF,RSP 3) IN_PORT
256 | in_port=1,dl_type=0x894f,
nsh_spi=0x4,nsh_si=254
(NSH, SFF1 Ingress from SFF2)
IN_PORT
5 Match Any Drop

Table: Table Transport Egress

Administering SFC OF Renderer

To use the SFC OpenFlow Renderer Karaf, at least the following Karaf features must be installed.

  • odl-openflowplugin-nxm-extensions
  • odl-openflowplugin-flow-services
  • odl-sfc-provider
  • odl-sfc-model
  • odl-sfc-openflow-renderer
  • odl-sfc-ui (optional)

Since OpenDaylight Karaf features internally install dependent features all of the above features can be installed by simply installing the ‘’odl-sfc-openflow-renderer’’ feature.

The following command can be used to view all of the currently installed Karaf features:

opendaylight-user@root>feature:list -i

Or, pipe the command to a grep to see a subset of the currently installed Karaf features:

opendaylight-user@root>feature:list -i | grep sfc

To install a particular feature, use the Karaf feature:install command.

SFC OF Renderer Tutorial

Overview

In this tutorial, the VXLAN-GPE NSH encapsulations will be shown. The following Network Topology diagram is a logical view of the SFFs and SFs involved in creating the Service Chains.

SFC OpenFlow Renderer Typical Network Topology

SFC OpenFlow Renderer Typical Network Topology

Prerequisites

To use this example, SFF OpenFlow switches must be created and connected as illustrated above. Additionally, the SFs must be created and connected.

Note that RSP symmetry depends on the Service Function Path symmetric field, if present. If not, the RSP will be symmetric if any of the SFs involved in the chain has the bidirectional field set to true.

Target Environment

The target environment is not important, but this use-case was created and tested on Linux.

Instructions

The steps to use this tutorial are as follows. The referenced configuration in the steps is listed in the following sections.

There are numerous ways to send the configuration. In the following configuration chapters, the appropriate curl command is shown for each configuration to be sent, including the URL.

Steps to configure the SFC OF Renderer tutorial:

  1. Send the SF RESTCONF configuration
  2. Send the SFF RESTCONF configuration
  3. Send the SFC RESTCONF configuration
  4. Send the SFP RESTCONF configuration
  5. The RSP will be created internally when the SFP is created.

Once the configuration has been successfully created, query the Rendered Service Paths with either the SFC UI or via RESTCONF. Notice that the RSP is symmetrical, so the following 2 RSPs will be created:

  • sfc-path1-Path-<RSP-ID>
  • sfc-path1-Path-<RSP-ID>-Reverse

At this point the Service Chains have been created, and the OpenFlow Switches are programmed to steer traffic through the Service Chain. Traffic can now be injected from a client into the Service Chain. To debug problems, the OpenFlow tables can be dumped with the following commands, assuming SFF1 is called s1 and SFF2 is called s2.

sudo ovs-ofctl -O OpenFlow13  dump-flows s1
sudo ovs-ofctl -O OpenFlow13  dump-flows s2

In all the following configuration sections, replace the ${JSON} string with the appropriate JSON configuration. Also, change the localhost destination in the URL accordingly.

SFC OF Renderer NSH Tutorial

The following configuration sections show how to create the different elements using NSH encapsulation.

NSH Service Function configuration

The Service Function configuration can be sent with the following command:

curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache"
--data '${JSON}' -X PUT --user
admin:admin http://localhost:8181/restconf/config/service-function:service-functions/

SF configuration JSON.

{
 "service-functions": {
   "service-function": [
     {
       "name": "sf1",
       "type": "http-header-enrichment",
       "ip-mgmt-address": "10.0.0.2",
       "sf-data-plane-locator": [
         {
           "name": "sf1dpl",
           "ip": "10.0.0.10",
           "port": 4789,
           "transport": "service-locator:vxlan-gpe",
           "service-function-forwarder": "sff1"
         }
       ]
     },
     {
       "name": "sf2",
       "type": "firewall",
       "ip-mgmt-address": "10.0.0.3",
       "sf-data-plane-locator": [
         {
           "name": "sf2dpl",
            "ip": "10.0.0.20",
            "port": 4789,
            "transport": "service-locator:vxlan-gpe",
           "service-function-forwarder": "sff2"
         }
       ]
     }
   ]
 }
}
NSH Service Function Forwarder configuration

The Service Function Forwarder configuration can be sent with the following command:

curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache" --data '${JSON}' -X PUT --user admin:admin http://localhost:8181/restconf/config/service-function-forwarder:service-function-forwarders/

SFF configuration JSON.

{
 "service-function-forwarders": {
   "service-function-forwarder": [
     {
       "name": "sff1",
       "service-node": "openflow:2",
       "sff-data-plane-locator": [
         {
           "name": "sff1dpl",
           "data-plane-locator":
           {
               "ip": "10.0.0.1",
               "port": 4789,
               "transport": "service-locator:vxlan-gpe"
           }
         }
       ],
       "service-function-dictionary": [
         {
           "name": "sf1",
           "sff-sf-data-plane-locator":
           {
               "sf-dpl-name": "sf1dpl",
               "sff-dpl-name": "sff1dpl"
           }
         }
       ]
     },
     {
       "name": "sff2",
       "service-node": "openflow:3",
       "sff-data-plane-locator": [
         {
           "name": "sff2dpl",
           "data-plane-locator":
           {
               "ip": "10.0.0.2",
               "port": 4789,
               "transport": "service-locator:vxlan-gpe"
           }
         }
       ],
       "service-function-dictionary": [
         {
           "name": "sf2",
           "sff-sf-data-plane-locator":
           {
               "sf-dpl-name": "sf2dpl",
               "sff-dpl-name": "sff2dpl"
           }
         }
       ]
     }
   ]
 }
}
NSH Service Function Chain configuration

The Service Function Chain configuration can be sent with the following command:

curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache"
--data '${JSON}' -X PUT --user
admin:admin http://localhost:8181/restconf/config/service-function-chain:service-function-chains/

SFC configuration JSON.

{
 "service-function-chains": {
   "service-function-chain": [
     {
       "name": "sfc-chain1",
       "sfc-service-function": [
         {
           "name": "hdr-enrich-abstract1",
           "type": "http-header-enrichment"
         },
         {
           "name": "firewall-abstract1",
           "type": "firewall"
         }
       ]
     }
   ]
 }
}
NSH Service Function Path configuration

The Service Function Path configuration can be sent with the following command:

curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache" --data '${JSON}' -X PUT --user admin:admin http://localhost:8181/restconf/config/service-function-path:service-function-paths/

SFP configuration JSON.

{
  "service-function-paths": {
    "service-function-path": [
      {
        "name": "sfc-path1",
        "service-chain-name": "sfc-chain1",
        "transport-type": "service-locator:vxlan-gpe",
        "symmetric": true
      }
    ]
  }
}
NSH Rendered Service Path Query

The following command can be used to query all of the created Rendered Service Paths:

curl -H "Content-Type: application/json" -H "Cache-Control: no-cache" -X GET --user admin:admin http://localhost:8181/restconf/operational/rendered-service-path:rendered-service-paths/
SFC OF Renderer MPLS Tutorial

The following configuration sections show how to create the different elements using MPLS encapsulation.

MPLS Service Function configuration

The Service Function configuration can be sent with the following command:

curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache"
--data '${JSON}' -X PUT --user
admin:admin http://localhost:8181/restconf/config/service-function:service-functions/

SF configuration JSON.

{
 "service-functions": {
   "service-function": [
     {
       "name": "sf1",
       "type": "http-header-enrichment",
       "ip-mgmt-address": "10.0.0.2",
       "sf-data-plane-locator": [
         {
           "name": "sf1-sff1",
           "mac": "00:00:08:01:02:01",
           "vlan-id": 1000,
           "transport": "service-locator:mac",
           "service-function-forwarder": "sff1"
         }
       ]
     },
     {
       "name": "sf2",
       "type": "firewall",
       "ip-mgmt-address": "10.0.0.3",
       "sf-data-plane-locator": [
         {
           "name": "sf2-sff2",
           "mac": "00:00:08:01:03:01",
           "vlan-id": 2000,
           "transport": "service-locator:mac",
           "service-function-forwarder": "sff2"
         }
       ]
     }
   ]
 }
}
MPLS Service Function Forwarder configuration

The Service Function Forwarder configuration can be sent with the following command:

curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache" --data '${JSON}' -X PUT --user admin:admin http://localhost:8181/restconf/config/service-function-forwarder:service-function-forwarders/

SFF configuration JSON.

{
 "service-function-forwarders": {
   "service-function-forwarder": [
     {
       "name": "sff1",
       "service-node": "openflow:2",
       "sff-data-plane-locator": [
         {
           "name": "ulSff1Ingress",
           "data-plane-locator":
           {
               "mpls-label": 100,
               "transport": "service-locator:mpls"
           },
           "service-function-forwarder-ofs:ofs-port":
           {
               "mac": "11:11:11:11:11:11",
               "port-id" : "1"
           }
         },
         {
           "name": "ulSff1ToSff2",
           "data-plane-locator":
           {
               "mpls-label": 101,
               "transport": "service-locator:mpls"
           },
           "service-function-forwarder-ofs:ofs-port":
           {
               "mac": "33:33:33:33:33:33",
               "port-id" : "2"
           }
         },
         {
           "name": "toSf1",
           "data-plane-locator":
           {
               "mac": "22:22:22:22:22:22",
               "vlan-id": 1000,
               "transport": "service-locator:mac",
           },
           "service-function-forwarder-ofs:ofs-port":
           {
               "mac": "33:33:33:33:33:33",
               "port-id" : "3"
           }
         }
       ],
       "service-function-dictionary": [
         {
           "name": "sf1",
           "sff-sf-data-plane-locator":
           {
               "sf-dpl-name": "sf1-sff1",
               "sff-dpl-name": "toSf1"
           }
         }
       ]
     },
     {
       "name": "sff2",
       "service-node": "openflow:3",
       "sff-data-plane-locator": [
         {
           "name": "ulSff2Ingress",
           "data-plane-locator":
           {
               "mpls-label": 101,
               "transport": "service-locator:mpls"
           },
           "service-function-forwarder-ofs:ofs-port":
           {
               "mac": "44:44:44:44:44:44",
               "port-id" : "1"
           }
         },
         {
           "name": "ulSff2Egress",
           "data-plane-locator":
           {
               "mpls-label": 102,
               "transport": "service-locator:mpls"
           },
           "service-function-forwarder-ofs:ofs-port":
           {
               "mac": "66:66:66:66:66:66",
               "port-id" : "2"
           }
         },
         {
           "name": "toSf2",
           "data-plane-locator":
           {
               "mac": "55:55:55:55:55:55",
               "vlan-id": 2000,
               "transport": "service-locator:mac"
           },
           "service-function-forwarder-ofs:ofs-port":
           {
               "port-id" : "3"
           }
         }
       ],
       "service-function-dictionary": [
         {
           "name": "sf2",
           "sff-sf-data-plane-locator":
           {
               "sf-dpl-name": "sf2-sff2",
               "sff-dpl-name": "toSf2"

           },
           "service-function-forwarder-ofs:ofs-port":
           {
               "port-id" : "3"
           }
         }
       ]
     }
   ]
 }
}
MPLS Service Function Chain configuration

The Service Function Chain configuration can be sent with the following command:

curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache"
 --data '${JSON}' -X PUT --user admin:admin
 http://localhost:8181/restconf/config/service-function-chain:service-function-chains/

SFC configuration JSON.

{
 "service-function-chains": {
   "service-function-chain": [
     {
       "name": "sfc-chain1",
       "sfc-service-function": [
         {
           "name": "hdr-enrich-abstract1",
           "type": "http-header-enrichment"
         },
         {
           "name": "firewall-abstract1",
           "type": "firewall"
         }
       ]
     }
   ]
 }
}
MPLS Service Function Path configuration

The Service Function Path configuration can be sent with the following command. This will internally trigger the Rendered Service Paths to be created.

curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache"
--data '${JSON}' -X PUT --user admin:admin
 http://localhost:8181/restconf/config/service-function-path:service-function-paths/

SFP configuration JSON.

{
  "service-function-paths": {
    "service-function-path": [
      {
        "name": "sfc-path1",
        "service-chain-name": "sfc-chain1",
        "transport-type": "service-locator:mpls",
        "symmetric": true
      }
    ]
  }
}

The following command can be used to query all of the Rendered Service Paths that were created when the Service Function Path was created:

curl -H "Content-Type: application/json" -H "Cache-Control: no-cache" -X GET
--user admin:admin http://localhost:8181/restconf/operational/rendered-service-path:rendered-service-paths/

SFC IOS XE Renderer User Guide

Overview

The early Service Function Chaining (SFC) renderer for IOS-XE devices (SFC IOS-XE renderer) implements Service Chaining functionality on IOS-XE capable switches. It listens for the creation of a Rendered Service Path (RSP) and sets up Service Function Forwarders (SFF) that are hosted on IOS-XE switches to steer traffic through the service chain.

Common acronyms used in the following sections:

  • SF - Service Function
  • SFF - Service Function Forwarder
  • SFC - Service Function Chain
  • SP - Service Path
  • SFP - Service Function Path
  • RSP - Rendered Service Path
  • LSF - Local Service Forwarder
  • RSF - Remote Service Forwarder

SFC IOS-XE Renderer Architecture

When the SFC IOS-XE renderer is initialized, all required listeners are registered to handle incoming data. It involves CSR/IOS-XE NodeListener which stores data about all configurable devices including their mountpoints (used here as databrokers), ServiceFunctionListener, ServiceForwarderListener (see mapping) and RenderedPathListener used to listen for RSP changes. When the SFC IOS-XE renderer is invoked, RenderedPathListener calls the IosXeRspProcessor which processes the RSP change and creates all necessary Service Paths and Remote Service Forwarders (if necessary) on IOS-XE devices.

Service Path details

Each Service Path is defined by index (represented by NSP) and contains service path entries. Each entry has appropriate service index (NSI) and definition of next hop. Next hop can be Service Function, different Service Function Forwarder or definition of end of chain - terminate. After terminating, the packet is sent to destination. If a SFF is defined as a next hop, it has to be present on device in the form of Remote Service Forwarder. RSFs are also created during RSP processing.

Example of Service Path:

service-chain service-path 200
   service-index 255 service-function firewall-1
   service-index 254 service-function dpi-1
   service-index 253 terminate

Mapping to IOS-XE SFC entities

Renderer contains mappers for SFs and SFFs. IOS-XE capable device is using its own definition of Service Functions and Service Function Forwarders according to appropriate .yang file. ServiceFunctionListener serves as a listener for SF changes. If SF appears in datastore, listener extracts its management ip address and looks into cached IOS-XE nodes. If some of available nodes match, Service function is mapped in IosXeServiceFunctionMapper to be understandable by IOS-XE device and it’s written into device’s config. ServiceForwarderListener is used in a similar way. All SFFs with suitable management ip address it mapped in IosXeServiceForwarderMapper. Remapped SFFs are configured as a Local Service Forwarders. It is not possible to directly create Remote Service Forwarder using IOS-XE renderer. RSF is created only during RSP processing.

Administering SFC IOS-XE renderer

To use the SFC IOS-XE Renderer Karaf, at least the following Karaf features must be installed:

  • odl-aaa-shiro
  • odl-sfc-model
  • odl-sfc-provider
  • odl-restconf
  • odl-netconf-topology
  • odl-sfc-ios-xe-renderer

SFC IOS-XE renderer Tutorial

Overview

This tutorial is a simple example how to create Service Path on IOS-XE capable device using IOS-XE renderer

Preconditions

To connect to IOS-XE device, it is necessary to use several modified yang models and override device’s ones. All .yang files are in the Yang/netconf folder in the sfc-ios-xe-renderer module in the SFC project. These files have to be copied to the cache/schema directory, before Karaf is started. After that, custom capabilities have to be sent to network-topology:

  • PUT ./config/network-topology:network-topology/topology/topology-netconf/node/<device-name>

    <node xmlns="urn:TBD:params:xml:ns:yang:network-topology">
      <node-id>device-name</node-id>
      <host xmlns="urn:opendaylight:netconf-node-topology">device-ip</host>
      <port xmlns="urn:opendaylight:netconf-node-topology">2022</port>
      <username xmlns="urn:opendaylight:netconf-node-topology">login</username>
      <password xmlns="urn:opendaylight:netconf-node-topology">password</password>
      <tcp-only xmlns="urn:opendaylight:netconf-node-topology">false</tcp-only>
      <keepalive-delay xmlns="urn:opendaylight:netconf-node-topology">0</keepalive-delay>
      <yang-module-capabilities xmlns="urn:opendaylight:netconf-node-topology">
         <override>true</override>
         <capability xmlns="urn:opendaylight:netconf-node-topology">
            urn:ietf:params:xml:ns:yang:ietf-inet-types?module=ietf-inet-types&amp;revision=2013-07-15
         </capability>
         <capability xmlns="urn:opendaylight:netconf-node-topology">
            urn:ietf:params:xml:ns:yang:ietf-yang-types?module=ietf-yang-types&amp;revision=2013-07-15
         </capability>
         <capability xmlns="urn:opendaylight:netconf-node-topology">
            urn:ios?module=ned&amp;revision=2016-03-08
         </capability>
         <capability xmlns="urn:opendaylight:netconf-node-topology">
            http://tail-f.com/yang/common?module=tailf-common&amp;revision=2015-05-22
         </capability>
         <capability xmlns="urn:opendaylight:netconf-node-topology">
            http://tail-f.com/yang/common?module=tailf-meta-extensions&amp;revision=2013-11-07
         </capability>
         <capability xmlns="urn:opendaylight:netconf-node-topology">
            http://tail-f.com/yang/common?module=tailf-cli-extensions&amp;revision=2015-03-19
         </capability>
      </yang-module-capabilities>
    </node>
    

Note

The device name in the URL and in the XML must match.

Instructions

When the IOS-XE renderer is installed, all NETCONF nodes in topology-netconf are processed and all capable nodes with accessible mountpoints are cached. The first step is to create LSF on node.

Service Function Forwarder configuration

  • PUT ./config/service-function-forwarder:service-function-forwarders

    {
        "service-function-forwarders": {
            "service-function-forwarder": [
                {
                    "name": "CSR1Kv-2",
                    "ip-mgmt-address": "172.25.73.23",
                    "sff-data-plane-locator": [
                        {
                            "name": "CSR1Kv-2-dpl",
                            "data-plane-locator": {
                                "transport": "service-locator:vxlan-gpe",
                                "port": 6633,
                                "ip": "10.99.150.10"
                            }
                        }
                    ]
                }
            ]
        }
    }
    

If the IOS-XE node with appropriate management IP exists, this configuration is mapped and LSF is created on the device. The same approach is used for Service Functions.

  • PUT ./config/service-function:service-functions

    {
        "service-functions": {
            "service-function": [
                {
                    "name": "Firewall",
                    "ip-mgmt-address": "172.25.73.23",
                    "type": "firewall",
                    "sf-data-plane-locator": [
                        {
                            "name": "firewall-dpl",
                            "port": 6633,
                            "ip": "12.1.1.2",
                            "transport": "service-locator:gre",
                            "service-function-forwarder": "CSR1Kv-2"
                        }
                    ]
                },
                {
                    "name": "Dpi",
                    "ip-mgmt-address": "172.25.73.23",
                    "type":"dpi",
                    "sf-data-plane-locator": [
                        {
                            "name": "dpi-dpl",
                            "port": 6633,
                            "ip": "12.1.1.1",
                            "transport": "service-locator:gre",
                            "service-function-forwarder": "CSR1Kv-2"
                        }
                    ]
                },
                {
                    "name": "Qos",
                    "ip-mgmt-address": "172.25.73.23",
                    "type":"qos",
                    "sf-data-plane-locator": [
                        {
                            "name": "qos-dpl",
                            "port": 6633,
                            "ip": "12.1.1.4",
                            "transport": "service-locator:gre",
                            "service-function-forwarder": "CSR1Kv-2"
                        }
                    ]
                }
            ]
        }
    }
    

All these SFs are configured on the same device as the LSF. The next step is to prepare Service Function Chain.

  • PUT ./config/service-function-chain:service-function-chains/

    {
        "service-function-chains": {
            "service-function-chain": [
                {
                    "name": "CSR3XSF",
                    "sfc-service-function": [
                        {
                            "name": "Firewall",
                            "type": "firewall"
                        },
                        {
                            "name": "Dpi",
                            "type": "dpi"
                        },
                        {
                            "name": "Qos",
                            "type": "qos"
                        }
                    ]
                }
            ]
        }
    }
    

Service Function Path:

  • PUT ./config/service-function-path:service-function-paths/

    {
        "service-function-paths": {
            "service-function-path": [
                {
                    "name": "CSR3XSF-Path",
                    "service-chain-name": "CSR3XSF",
                    "starting-index": 255,
                    "symmetric": "true"
                }
            ]
        }
    }
    

Without a classifier, there is possibility to POST RSP directly.

  • POST ./operations/rendered-service-path:create-rendered-path

    {
      "input": {
          "name": "CSR3XSF-Path-RSP",
          "parent-service-function-path": "CSR3XSF-Path"
      }
    }
    

The resulting configuration:

!
service-chain service-function-forwarder local
  ip address 10.99.150.10
!
service-chain service-function firewall
ip address 12.1.1.2
  encapsulation gre enhanced divert
!
service-chain service-function dpi
ip address 12.1.1.1
  encapsulation gre enhanced divert
!
service-chain service-function qos
ip address 12.1.1.4
  encapsulation gre enhanced divert
!
service-chain service-path 1
  service-index 255 service-function firewall
  service-index 254 service-function dpi
  service-index 253 service-function qos
  service-index 252 terminate
!
service-chain service-path 2
  service-index 255 service-function qos
  service-index 254 service-function dpi
  service-index 253 service-function firewall
  service-index 252 terminate
!

Service Path 1 is direct, Service Path 2 is reversed. Path numbers may vary.

Service Function Scheduling Algorithms

Overview

When creating the Rendered Service Path, the origin SFC controller chose the first available service function from a list of service function names. This may result in many issues such as overloaded service functions and a longer service path as SFC has no means to understand the status of service functions and network topology. The service function selection framework supports at least four algorithms (Random, Round Robin, Load Balancing and Shortest Path) to select the most appropriate service function when instantiating the Rendered Service Path. In addition, it is an extensible framework that allows 3rd party selection algorithm to be plugged in.

Architecture

The following figure illustrates the service function selection framework and algorithms.

SF Selection Architecture

SF Selection Architecture

A user has three different ways to select one service function selection algorithm:

  1. Integrated RESTCONF Calls. OpenStack and/or other administration system could provide plugins to call the APIs to select one scheduling algorithm.
  2. Command line tools. Command line tools such as curl or browser plugins such as POSTMAN (for Google Chrome) and RESTClient (for Mozilla Firefox) could select schedule algorithm by making RESTCONF calls.
  3. SFC-UI. Now the SFC-UI provides an option for choosing a selection algorithm when creating a Rendered Service Path.

The RESTCONF northbound SFC API provides GUI/RESTCONF interactions for choosing the service function selection algorithm. MD-SAL data store provides all supported service function selection algorithms, and provides APIs to enable one of the provided service function selection algorithms. Once a service function selection algorithm is enabled, the service function selection algorithm will work when creating a Rendered Service Path.

Select SFs with Scheduler

Administrator could use both the following ways to select one of the selection algorithm when creating a Rendered Service Path.

  • Command line tools. Command line tools includes Linux commands curl or even browser plugins such as POSTMAN(for Google Chrome) or RESTClient(for Mozilla Firefox). In this case, the following JSON content is needed at the moment: Service_function_schudule_type.json

    {
      "service-function-scheduler-types": {
        "service-function-scheduler-type": [
          {
            "name": "random",
            "type": "service-function-scheduler-type:random",
            "enabled": false
          },
          {
            "name": "roundrobin",
            "type": "service-function-scheduler-type:round-robin",
            "enabled": true
          },
          {
            "name": "loadbalance",
            "type": "service-function-scheduler-type:load-balance",
            "enabled": false
          },
          {
            "name": "shortestpath",
            "type": "service-function-scheduler-type:shortest-path",
            "enabled": false
          }
        ]
      }
    }
    

    If using the Linux curl command, it could be:

    curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache"
    --data '$${Service_function_schudule_type.json}' -X PUT
    --user admin:admin http://localhost:8181/restconf/config/service-function-scheduler-type:service-function-scheduler-types/
    

Here is also a snapshot for using the RESTClient plugin:

Mozilla Firefox RESTClient

Mozilla Firefox RESTClient

  • SFC-UI.SFC-UI provides a drop down menu for service function selection algorithm. Here is a snapshot for the user interaction from SFC-UI when creating a Rendered Service Path.
Karaf Web UI

Karaf Web UI

Note

Some service function selection algorithms in the drop list are not implemented yet. Only the first three algorithms are committed at the moment.

Random

Select Service Function from the name list randomly.

Overview

The Random algorithm is used to select one Service Function from the name list which it gets from the Service Function Type randomly.

Prerequisites
  • Service Function information are stored in datastore.
  • Either no algorithm or the Random algorithm is selected.
Target Environment

The Random algorithm will work either no algorithm type is selected or the Random algorithm is selected.

Instructions

Once the plugins are installed into Karaf successfully, a user can use his favorite method to select the Random scheduling algorithm type. There are no special instructions for using the Random algorithm.

Round Robin

Select Service Function from the name list in Round Robin manner.

Overview

The Round Robin algorithm is used to select one Service Function from the name list which it gets from the Service Function Type in a Round Robin manner, this will balance workloads to all Service Functions. However, this method cannot help all Service Functions load the same workload because it’s flow-based Round Robin.

Prerequisites
  • Service Function information are stored in datastore.
  • Round Robin algorithm is selected
Target Environment

The Round Robin algorithm will work one the Round Robin algorithm is selected.

Instructions

Once the plugins are installed into Karaf successfully, a user can use his favorite method to select the Round Robin scheduling algorithm type. There are no special instructions for using the Round Robin algorithm.

Load Balance Algorithm

Select appropriate Service Function by actual CPU utilization.

Overview

The Load Balance Algorithm is used to select appropriate Service Function by actual CPU utilization of service functions. The CPU utilization of service function obtained from monitoring information reported via NETCONF.

Prerequisites
  • CPU-utilization for Service Function.
  • NETCONF server.
  • NETCONF client.
  • Each VM has a NETCONF server and it could work with NETCONF client well.
Instructions

Set up VMs as Service Functions. enable NETCONF server in VMs. Ensure that you specify them separately. For example:

  1. Set up 4 VMs include 2 SFs’ type are Firewall, Others are Napt44. Name them as firewall-1, firewall-2, napt44-1, napt44-2 as Service Function. The four VMs can run either the same server or different servers.
  2. Install NETCONF server on every VM and enable it. More information on NETCONF can be found on the OpenDaylight wiki here: https://wiki.opendaylight.org/view/OpenDaylight_Controller:Config:Examples:Netconf:Manual_netopeer_installation
  3. Get Monitoring data from NETCONF server. These monitoring data should be get from the NETCONF server which is running in VMs. The following static XML data is an example:

static XML data like this:

<?xml version="1.0" encoding="UTF-8"?>
<service-function-description-monitor-report>
  <SF-description>
    <number-of-dataports>2</number-of-dataports>
    <capabilities>
      <supported-packet-rate>5</supported-packet-rate>
      <supported-bandwidth>10</supported-bandwidth>
      <supported-ACL-number>2000</supported-ACL-number>
      <RIB-size>200</RIB-size>
      <FIB-size>100</FIB-size>
      <ports-bandwidth>
        <port-bandwidth>
          <port-id>1</port-id>
          <ipaddress>10.0.0.1</ipaddress>
          <macaddress>00:1e:67:a2:5f:f4</macaddress>
          <supported-bandwidth>20</supported-bandwidth>
        </port-bandwidth>
        <port-bandwidth>
          <port-id>2</port-id>
          <ipaddress>10.0.0.2</ipaddress>
          <macaddress>01:1e:67:a2:5f:f6</macaddress>
          <supported-bandwidth>10</supported-bandwidth>
        </port-bandwidth>
      </ports-bandwidth>
    </capabilities>
  </SF-description>
  <SF-monitoring-info>
    <liveness>true</liveness>
    <resource-utilization>
        <packet-rate-utilization>10</packet-rate-utilization>
        <bandwidth-utilization>15</bandwidth-utilization>
        <CPU-utilization>12</CPU-utilization>
        <memory-utilization>17</memory-utilization>
        <available-memory>8</available-memory>
        <RIB-utilization>20</RIB-utilization>
        <FIB-utilization>25</FIB-utilization>
        <power-utilization>30</power-utilization>
        <SF-ports-bandwidth-utilization>
          <port-bandwidth-utilization>
            <port-id>1</port-id>
            <bandwidth-utilization>20</bandwidth-utilization>
          </port-bandwidth-utilization>
          <port-bandwidth-utilization>
            <port-id>2</port-id>
            <bandwidth-utilization>30</bandwidth-utilization>
          </port-bandwidth-utilization>
        </SF-ports-bandwidth-utilization>
    </resource-utilization>
  </SF-monitoring-info>
</service-function-description-monitor-report>
  1. Unzip SFC release tarball.
  2. Run SFC: ${sfc}/bin/karaf. More information on Service Function Chaining can be found on the OpenDaylight SFC’s wiki page: https://wiki.opendaylight.org/view/Service_Function_Chaining:Main
  1. Deploy the SFC2 (firewall-abstract2⇒napt44-abstract2) and click button to Create Rendered Service Path in SFC UI (http://localhost:8181/sfc/index.html).
  2. Verify the Rendered Service Path to ensure the CPU utilization of the selected hop is the minimum one among all the service functions with same type. The correct RSP is firewall-1⇒napt44-2

Shortest Path Algorithm

Select appropriate Service Function by Dijkstra’s algorithm. Dijkstra’s algorithm is an algorithm for finding the shortest paths between nodes in a graph.

Overview

The Shortest Path Algorithm is used to select appropriate Service Function by actual topology.

Prerequisites
Instructions
  1. Unzip SFC release tarball.
  2. Run SFC: ${sfc}/bin/karaf.
  3. Depoly SFFs and SFs. import the service-function-forwarders.json and service-functions.json in UI (http://localhost:8181/sfc/index.html#/sfc/config)

service-function-forwarders.json:

{
  "service-function-forwarders": {
    "service-function-forwarder": [
      {
        "name": "SFF-br1",
        "service-node": "OVSDB-test01",
        "rest-uri": "http://localhost:5001",
        "sff-data-plane-locator": [
          {
            "name": "eth0",
            "service-function-forwarder-ovs:ovs-bridge": {
              "uuid": "4c3778e4-840d-47f4-b45e-0988e514d26c",
              "bridge-name": "br-tun"
            },
            "data-plane-locator": {
              "port": 5000,
              "ip": "192.168.1.1",
              "transport": "service-locator:vxlan-gpe"
            }
          }
        ],
        "service-function-dictionary": [
          {
            "sff-sf-data-plane-locator": {
               "sf-dpl-name": "sf1dpl",
               "sff-dpl-name": "sff1dpl"
            },
            "name": "napt44-1",
            "type": "napt44"
          },
          {
            "sff-sf-data-plane-locator": {
               "sf-dpl-name": "sf2dpl",
               "sff-dpl-name": "sff2dpl"
            },
            "name": "firewall-1",
            "type": "firewall"
          }
        ],
        "connected-sff-dictionary": [
          {
            "name": "SFF-br3"
          }
        ]
      },
      {
        "name": "SFF-br2",
        "service-node": "OVSDB-test01",
        "rest-uri": "http://localhost:5002",
        "sff-data-plane-locator": [
          {
            "name": "eth0",
            "service-function-forwarder-ovs:ovs-bridge": {
              "uuid": "fd4d849f-5140-48cd-bc60-6ad1f5fc0a1",
              "bridge-name": "br-tun"
            },
            "data-plane-locator": {
              "port": 5000,
              "ip": "192.168.1.2",
              "transport": "service-locator:vxlan-gpe"
            }
          }
        ],
        "service-function-dictionary": [
          {
            "sff-sf-data-plane-locator": {
               "sf-dpl-name": "sf1dpl",
               "sff-dpl-name": "sff1dpl"
            },
            "name": "napt44-2",
            "type": "napt44"
          },
          {
            "sff-sf-data-plane-locator": {
               "sf-dpl-name": "sf2dpl",
               "sff-dpl-name": "sff2dpl"
            },
            "name": "firewall-2",
            "type": "firewall"
          }
        ],
        "connected-sff-dictionary": [
          {
            "name": "SFF-br3"
          }
        ]
      },
      {
        "name": "SFF-br3",
        "service-node": "OVSDB-test01",
        "rest-uri": "http://localhost:5005",
        "sff-data-plane-locator": [
          {
            "name": "eth0",
            "service-function-forwarder-ovs:ovs-bridge": {
              "uuid": "fd4d849f-5140-48cd-bc60-6ad1f5fc0a4",
              "bridge-name": "br-tun"
            },
            "data-plane-locator": {
              "port": 5000,
              "ip": "192.168.1.2",
              "transport": "service-locator:vxlan-gpe"
            }
          }
        ],
        "service-function-dictionary": [
          {
            "sff-sf-data-plane-locator": {
               "sf-dpl-name": "sf1dpl",
               "sff-dpl-name": "sff1dpl"
            },
            "name": "test-server",
            "type": "dpi"
          },
          {
            "sff-sf-data-plane-locator": {
               "sf-dpl-name": "sf2dpl",
               "sff-dpl-name": "sff2dpl"
            },
            "name": "test-client",
            "type": "dpi"
          }
        ],
        "connected-sff-dictionary": [
          {
            "name": "SFF-br1"
          },
          {
            "name": "SFF-br2"
          }
        ]
      }
    ]
  }
}

service-functions.json:

{
  "service-functions": {
    "service-function": [
      {
        "rest-uri": "http://localhost:10001",
        "ip-mgmt-address": "10.3.1.103",
        "sf-data-plane-locator": [
          {
            "name": "preferred",
            "port": 10001,
            "ip": "10.3.1.103",
            "service-function-forwarder": "SFF-br1"
          }
        ],
        "name": "napt44-1",
        "type": "napt44"
      },
      {
        "rest-uri": "http://localhost:10002",
        "ip-mgmt-address": "10.3.1.103",
        "sf-data-plane-locator": [
          {
            "name": "master",
            "port": 10002,
            "ip": "10.3.1.103",
            "service-function-forwarder": "SFF-br2"
          }
        ],
        "name": "napt44-2",
        "type": "napt44"
      },
      {
        "rest-uri": "http://localhost:10003",
        "ip-mgmt-address": "10.3.1.103",
        "sf-data-plane-locator": [
          {
            "name": "1",
            "port": 10003,
            "ip": "10.3.1.102",
            "service-function-forwarder": "SFF-br1"
          }
        ],
        "name": "firewall-1",
        "type": "firewall"
      },
      {
        "rest-uri": "http://localhost:10004",
        "ip-mgmt-address": "10.3.1.103",
        "sf-data-plane-locator": [
          {
            "name": "2",
            "port": 10004,
            "ip": "10.3.1.101",
            "service-function-forwarder": "SFF-br2"
          }
        ],
        "name": "firewall-2",
        "type": "firewall"
      },
      {
        "rest-uri": "http://localhost:10005",
        "ip-mgmt-address": "10.3.1.103",
        "sf-data-plane-locator": [
          {
            "name": "3",
            "port": 10005,
            "ip": "10.3.1.104",
            "service-function-forwarder": "SFF-br3"
          }
        ],
        "name": "test-server",
        "type": "dpi"
      },
      {
        "rest-uri": "http://localhost:10006",
        "ip-mgmt-address": "10.3.1.103",
        "sf-data-plane-locator": [
          {
            "name": "4",
            "port": 10006,
            "ip": "10.3.1.102",
            "service-function-forwarder": "SFF-br3"
          }
        ],
        "name": "test-client",
        "type": "dpi"
      }
    ]
  }
}

The deployed topology like this:

          +----+           +----+          +----+
          |sff1|+----------|sff3|---------+|sff2|
          +----+           +----+          +----+
            |                                  |
     +--------------+                   +--------------+
     |              |                   |              |
+----------+   +--------+          +----------+   +--------+
|firewall-1|   |napt44-1|          |firewall-2|   |napt44-2|
+----------+   +--------+          +----------+   +--------+
  • Deploy the SFC2(firewall-abstract2⇒napt44-abstract2), select “Shortest Path” as schedule type and click button to Create Rendered Service Path in SFC UI (http://localhost:8181/sfc/index.html).
select schedule type

select schedule type

  • Verify the Rendered Service Path to ensure the selected hops are linked in one SFF. The correct RSP is firewall-1⇒napt44-1 or firewall-2⇒napt44-2. The first SF type is Firewall in Service Function Chain. So the algorithm will select first Hop randomly among all the SFs type is Firewall. Assume the first selected SF is firewall-2. All the path from firewall-1 to SF which type is Napt44 are list:
    • Path1: firewall-2 → sff2 → napt44-2
    • Path2: firewall-2 → sff2 → sff3 → sff1 → napt44-1 The shortest path is Path1, so the selected next hop is napt44-2.
rendered service path

rendered service path

Service Function Load Balancing User Guide

Overview

SFC Load-Balancing feature implements load balancing of Service Functions, rather than a one-to-one mapping between Service-Function-Forwarder and Service-Function.

Load Balancing Architecture

Service Function Groups (SFG) can replace Service Functions (SF) in the Rendered Path model. A Service Path can only be defined using SFGs or SFs, but not a combination of both.

Relevant objects in the YANG model are as follows:

  1. Service-Function-Group-Algorithm:

    Service-Function-Group-Algorithms {
        Service-Function-Group-Algorithm {
            String name
            String type
        }
    }
    
    Available types: ALL, SELECT, INDIRECT, FAST_FAILURE
    
  2. Service-Function-Group:

    Service-Function-Groups {
        Service-Function-Group {
            String name
            String serviceFunctionGroupAlgorithmName
            String type
            String groupId
            Service-Function-Group-Element {
                String service-function-name
                int index
            }
        }
    }
    
  3. ServiceFunctionHop: holds a reference to a name of SFG (or SF)

Tutorials

This tutorial will explain how to create a simple SFC configuration, with SFG instead of SF. In this example, the SFG will include two existing SF.

Setup SFC

For general SFC setup and scenarios, please see the SFC wiki page: https://wiki.opendaylight.org/view/Service_Function_Chaining:Main#SFC_101

Create an algorithm

POST - http://127.0.0.1:8181/restconf/config/service-function-group-algorithm:service-function-group-algorithms

{
    "service-function-group-algorithm": [
      {
        "name": "alg1"
        "type": "ALL"
      }
   ]
}

(Header “content-type”: application/json)

Create a group

POST - http://127.0.0.1:8181/restconf/config/service-function-group:service-function-groups

{
    "service-function-group": [
    {
        "rest-uri": "http://localhost:10002",
        "ip-mgmt-address": "10.3.1.103",
        "algorithm": "alg1",
        "name": "SFG1",
        "type": "napt44",
        "sfc-service-function": [
            {
                "name":"napt44-104"
            },
            {
                "name":"napt44-103-1"
            }
        ]
      }
    ]
}

SFC Proof of Transit User Guide

Overview

Several deployments use traffic engineering, policy routing, segment routing or service function chaining (SFC) to steer packets through a specific set of nodes. In certain cases regulatory obligations or a compliance policy require to prove that all packets that are supposed to follow a specific path are indeed being forwarded across the exact set of nodes specified. I.e. if a packet flow is supposed to go through a series of service functions or network nodes, it has to be proven that all packets of the flow actually went through the service chain or collection of nodes specified by the policy. In case the packets of a flow weren’t appropriately processed, a proof of transit egress device would be required to identify the policy violation and take corresponding actions (e.g. drop or redirect the packet, send an alert etc.) corresponding to the policy.

Service Function Chaining (SFC) Proof of Transit (SFC PoT) implements Service Chaining Proof of Transit functionality on capable network devices. Proof of Transit defines mechanisms to securely prove that traffic transited the defined path. After the creation of an Rendered Service Path (RSP), a user can configure to enable SFC proof of transit on the selected RSP to effect the proof of transit.

To ensure that the data traffic follows a specified path or a function chain, meta-data is added to user traffic in the form of a header. The meta-data is based on a ‘share of a secret’ and provisioned by the SFC PoT configuration from ODL over a secure channel to each of the nodes in the SFC. This meta-data is updated at each of the service-hop while a designated node called the verifier checks whether the collected meta-data allows the retrieval of the secret.

The following diagram shows the overview and essentially utilizes Shamir’s secret sharing algorithm, where each service is given a point on the curve and when the packet travels through each service, it collects these points (meta-data) and a verifier node tries to re-construct the curve using the collected points, thus verifying that the packet traversed through all the service functions along the chain.

SFC Proof of Transit overview

SFC Proof of Transit overview

Transport options for different protocols includes a new TLV in SR header for Segment Routing, NSH Type-2 meta-data, IPv6 extension headers, IPv4 variants and for VXLAN-GPE. More details are captured in the following link.

In-situ OAM: https://github.com/CiscoDevNet/iOAM

Common acronyms used in the following sections:

  • SF - Service Function
  • SFF - Service Function Forwarder
  • SFC - Service Function Chain
  • SFP - Service Function Path
  • RSP - Rendered Service Path
  • SFC PoT - Service Function Chain Proof of Transit

SFC Proof of Transit Architecture

SFC PoT feature is implemented as a two-part implementation with a north-bound handler that augments the RSP while a south-bound renderer auto-generates the required parameters and passes it on to the nodes that belong to the SFC.

The north-bound feature is enabled via odl-sfc-pot feature while the south-bound renderer is enabled via the odl-sfc-pot-netconf-renderer feature. For the purposes of SFC PoT handling, both features must be installed.

RPC handlers to augment the RSP are part of SfcPotRpc while the RSP augmentation to enable or disable SFC PoT feature is done via SfcPotRspProcessor.

SFC Proof of Transit entities

In order to implement SFC Proof of Transit for a service function chain, an RSP is a pre-requisite to identify the SFC to enable SFC PoT on. SFC Proof of Transit for a particular RSP is enabled by an RPC request to the controller along with necessary parameters to control some of the aspects of the SFC Proof of Transit process.

The RPC handler identifies the RSP and adds PoT feature meta-data like enable/disable, number of PoT profiles, profiles refresh parameters etc., that directs the south-bound renderer appropriately when RSP changes are noticed via call-backs in the renderer handlers.

Administering SFC Proof of Transit

To use the SFC Proof of Transit Karaf, at least the following Karaf features must be installed:

  • odl-sfc-model
  • odl-sfc-provider
  • odl-sfc-netconf
  • odl-restconf
  • odl-netconf-topology
  • odl-netconf-connector-all
  • odl-sfc-pot

Please note that the odl-sfc-pot-netconf-renderer or other renderers in future must be installed for the feature to take full-effect. The details of the renderer features are described in other parts of this document.

SFC Proof of Transit Tutorial

Overview

This tutorial is a simple example how to configure Service Function Chain Proof of Transit using SFC POT feature.

Preconditions

To enable a device to handle SFC Proof of Transit, it is expected that the NETCONF node device advertise capability as under ioam-sb-pot.yang present under sfc-model/src/main/yang folder. It is also expected that base NETCONF support be enabled and its support capability advertised as capabilities.

NETCONF support:urn:ietf:params:netconf:base:1.0

PoT support: (urn:cisco:params:xml:ns:yang:sfc-ioam-sb-pot?revision=2017-01-12)sfc-ioam-sb-pot

It is also expected that the devices are netconf mounted and available in the topology-netconf store.

Instructions

When SFC Proof of Transit is installed, all netconf nodes in topology-netconf are processed and all capable nodes with accessible mountpoints are cached.

First step is to create the required RSP as is usually done using RSP creation steps in SFC main.

Once RSP name is available it is used to send a POST RPC to the controller similar to below:

POST - http://ODL-IP:8181/restconf/operations/sfc-ioam-nb-pot:enable-sfc-ioam-pot-rendered-path/

{
    "input":
    {
        "sfc-ioam-pot-rsp-name": "sfc-path-3sf3sff",
        "ioam-pot-enable":true,
        "ioam-pot-num-profiles":2,
        "ioam-pot-bit-mask":"bits32",
        "refresh-period-time-units":"milliseconds",
        "refresh-period-value":5000
    }
}

The following can be used to disable the SFC Proof of Transit on an RSP which disables the PoT feature.

POST - http://ODL-IP:8181/restconf/operations/sfc-ioam-nb-pot:disable-sfc-ioam-pot-rendered-path/

{
    "input":
    {
        "sfc-ioam-pot-rsp-name": "sfc-path-3sf3sff",
    }
}

SFC PoT NETCONF Renderer User Guide

Overview

The SFC Proof of Transit (PoT) NETCONF renderer implements SFC Proof of Transit functionality on NETCONF-capable devices, that have advertised support for in-situ OAM (iOAM) support.

It listens for an update to an existing RSP with enable or disable proof of transit support and adds the auto-generated SFC PoT configuration parameters to all the SFC hop nodes. The last node in the SFC is configured as a verifier node to allow SFC PoT process to be completed.

Common acronyms are used as below:

  • SF - Service Function
  • SFC - Service Function Chain
  • RSP - Rendered Service Path
  • SFF - Service Function Forwarder

Mapping to SFC entities

The renderer module listens to RSP updates in SfcPotNetconfRSPListener and triggers configuration generation in SfcPotNetconfIoam class. Node arrival and leaving are managed via SfcPotNetconfNodeManager and SfcPotNetconfNodeListener. In addition there is a timer thread that runs to generate configuration periodically to refresh the profiles in the nodes that are part of the SFC.

Administering SFC PoT NETCONF Renderer

To use the SFC Proof of Transit Karaf, the following Karaf features must be installed:

  • odl-sfc-model
  • odl-sfc-provider
  • odl-sfc-netconf
  • odl-restconf-all
  • odl-netconf-topology
  • odl-netconf-connector-all
  • odl-sfc-pot
  • odl-sfc-pot-netconf-renderer

SFC PoT NETCONF Renderer Tutorial

Overview

This tutorial is a simple example how to enable SFC PoT on NETCONF-capable devices.

Preconditions

The NETCONF-capable device will have to support sfc-ioam-sb-pot.yang file.

It is expected that a NETCONF-capable VPP device has Honeycomb (Hc2vpp) Java-based agent that helps to translate between NETCONF and VPP internal APIs.

More details are here: In-situ OAM: https://github.com/CiscoDevNet/iOAM

Steps

When the SFC PoT NETCONF renderer module is installed, all NETCONF nodes in topology-netconf are processed and all sfc-ioam-sb-pot yang capable nodes with accessible mountpoints are cached.

The first step is to create RSP for the SFC as per SFC guidelines above.

Enable SFC PoT is done on the RSP via RESTCONF to the ODL as outlined above.

Internally, the NETCONF renderer will act on the callback to a modified RSP that has PoT enabled.

In-situ OAM algorithms for auto-generation of SFC PoT parameters are generated automatically and sent to these nodes via NETCONF.

Logical Service Function Forwarder

Overview

Rationale

When the current SFC is deployed in a cloud environment, it is assumed that each switch connected to a Service Function is configured as a Service Function Forwarder and each Service Function is connected to its Service Function Forwarder depending on the Compute Node where the Virtual Machine is located.

Deploying SFC in Cloud Environments

As shown in the picture above, this solution allows the basic cloud use cases to be fulfilled, as for example, the ones required in OPNFV Brahmaputra, however, some advanced use cases like the transparent migration of VMs can not be implemented. The Logical Service Function Forwarder enables the following advanced use cases:

  1. Service Function mobility without service disruption
  2. Service Functions load balancing and failover

As shown in the picture below, the Logical Service Function Forwarder concept extends the current SFC northbound API to provide an abstraction of the underlying Data Center infrastructure. The Data Center underlaying network can be abstracted by a single SFF. This single SFF uses the logical port UUID as data plane locator to connect SFs globally and in a location-transparent manner. SFC makes use of Genius project to track the location of the SF’s logical ports.

Single Logical SFF concept

The SFC internally distributes the necessary flow state over the relevant switches based on the internal Data Center topology and the deployment of SFs.

Changes in data model

The Logical Service Function Forwarder concept extends the current SFC northbound API to provide an abstraction of the underlying Data Center infrastructure.

The Logical SFF simplifies the configuration of the current SFC data model by reducing the number of parameters to be be configured in every SFF, since the controller will discover those parameters by interacting with the services offered by the Genius project.

The following picture shows the Logical SFF data model. The model gets simplified as most of the configuration parameters of the current SFC data model are discovered in runtime. The complete YANG model can be found here logical SFF model.

Logical SFF data model

How to configure the Logical SFF

The following are examples to configure the Logical SFF:

curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache"
--data '${JSON}' -X PUT --user
admin:admin http://localhost:8181/restconf/config/restconf/config/service-function:service-functions/

Service Functions JSON.

{
"service-functions": {
    "service-function": [
        {
            "name": "firewall-1",
            "type": "firewall",
            "sf-data-plane-locator": [
                {
                    "name": "firewall-dpl",
                    "interface-name": "eccb57ae-5a2e-467f-823e-45d7bb2a6a9a",
                    "transport": "service-locator:eth-nsh",
                    "service-function-forwarder": "sfflogical1"

                }
            ]
        },
        {
            "name": "dpi-1",
            "type": "dpi",
            "sf-data-plane-locator": [
                {
                    "name": "dpi-dpl",
                    "interface-name": "df15ac52-e8ef-4e9a-8340-ae0738aba0c0",
                    "transport": "service-locator:eth-nsh",
                    "service-function-forwarder": "sfflogical1"
                }
            ]
        }
    ]
}
}
curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache"
--data '${JSON}' -X PUT --user
admin:admin http://localhost:8181/restconf/config/service-function-forwarder:service-function-forwarders/

Service Function Forwarders JSON.

{
"service-function-forwarders": {
    "service-function-forwarder": [
       {
            "name": "sfflogical1"
        }
    ]
}
}
curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache"
--data '${JSON}' -X PUT --user
admin:admin http://localhost:8181/restconf/config/service-function-chain:service-function-chains/

Service Function Chains JSON.

{
"service-function-chains": {
    "service-function-chain": [
        {
            "name": "SFC1",
            "sfc-service-function": [
                {
                    "name": "dpi-abstract1",
                    "type": "dpi"
                },
                {
                    "name": "firewall-abstract1",
                    "type": "firewall"
                }
            ]
        },
        {
            "name": "SFC2",
            "sfc-service-function": [
                {
                    "name": "dpi-abstract1",
                    "type": "dpi"
                }
            ]
        }
    ]
}
}
curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache"
--data '${JSON}' -X PUT --user
 admin:admin http://localhost:8182/restconf/config/service-function-chain:service-function-paths/

Service Function Paths JSON.

{
"service-function-paths": {
    "service-function-path": [
        {
            "name": "SFP1",
            "service-chain-name": "SFC1",
            "starting-index": 255,
            "symmetric": "true",
            "context-metadata": "NSH1",
            "transport-type": "service-locator:vxlan-gpe"

        }
    ]
}
}

As a result of above configuration, OpenDaylight renders the needed flows in all involved SFFs. Those flows implement:

  • Two Rendered Service Paths:
    • dpi-1 (SF1), firewall-1 (SF2)
    • firewall-1 (SF2), dpi-1 (SF1)
  • The communication between SFFs and SFs based on eth-nsh
  • The communication between SFFs based on vxlan-gpe

The following picture shows a topology and traffic flow (in green) which corresponds to the above configuration.

Logical SFF Example

Logical SFF Example

The Logical SFF functionality allows OpenDaylight to find out the SFFs holding the SFs involved in a path. In this example the SFFs affected are Node3 and Node4 thus the controller renders the flows containing NSH parameters just in those SFFs.

Here you have the new flows rendered in Node3 and Node4 which implement the NSH protocol. Every Rendered Service Path is represented by an NSP value. We provisioned a symmetric RSP so we get two NSPs: 8388613 and 5. Node3 holds the first SF of NSP 8388613 and the last SF of NSP 5. Node 4 holds the first SF of NSP 5 and the last SF of NSP 8388613. Both Node3 and Node4 will pop the NSH header when the received packet has gone through the last SF of its path.

Rendered flows Node 3

cookie=0x14, duration=59.264s, table=83, n_packets=0, n_bytes=0, priority=250,nsp=5 actions=goto_table:86
cookie=0x14, duration=59.194s, table=83, n_packets=0, n_bytes=0, priority=250,nsp=8388613 actions=goto_table:86
cookie=0x14, duration=59.257s, table=86, n_packets=0, n_bytes=0, priority=550,nsi=254,nsp=5 actions=load:0x8e0a37cc9094->NXM_NX_ENCAP_ETH_SRC[],load:0x6ee006b4c51e->NXM_NX_ENCAP_ETH_DST[],goto_table:87
cookie=0x14, duration=59.189s, table=86, n_packets=0, n_bytes=0, priority=550,nsi=255,nsp=8388613 actions=load:0x8e0a37cc9094->NXM_NX_ENCAP_ETH_SRC[],load:0x6ee006b4c51e->NXM_NX_ENCAP_ETH_DST[],goto_table:87
cookie=0xba5eba1100000203, duration=59.213s, table=87, n_packets=0, n_bytes=0, priority=650,nsi=253,nsp=5 actions=pop_nsh,set_field:6e:e0:06:b4:c5:1e->eth_src,resubmit(,17)
cookie=0xba5eba1100000201, duration=59.213s, table=87, n_packets=0, n_bytes=0, priority=650,nsi=254,nsp=5 actions=load:0x800->NXM_NX_REG6[],resubmit(,220)
cookie=0xba5eba1100000201, duration=59.188s, table=87, n_packets=0, n_bytes=0, priority=650,nsi=255,nsp=8388613 actions=load:0x800->NXM_NX_REG6[],resubmit(,220)
cookie=0xba5eba1100000201, duration=59.182s, table=87, n_packets=0, n_bytes=0, priority=650,nsi=254,nsp=8388613 actions=set_field:0->tun_id,output:6

Rendered Flows Node 4

cookie=0x14, duration=69.040s, table=83, n_packets=0, n_bytes=0, priority=250,nsp=5 actions=goto_table:86
cookie=0x14, duration=69.008s, table=83, n_packets=0, n_bytes=0, priority=250,nsp=8388613 actions=goto_table:86
cookie=0x14, duration=69.040s, table=86, n_packets=0, n_bytes=0, priority=550,nsi=255,nsp=5 actions=load:0xbea93873f4fa->NXM_NX_ENCAP_ETH_SRC[],load:0x214845ea85d->NXM_NX_ENCAP_ETH_DST[],goto_table:87
cookie=0x14, duration=69.005s, table=86, n_packets=0, n_bytes=0, priority=550,nsi=254,nsp=8388613 actions=load:0xbea93873f4fa->NXM_NX_ENCAP_ETH_SRC[],load:0x214845ea85d->NXM_NX_ENCAP_ETH_DST[],goto_table:87
cookie=0xba5eba1100000201, duration=69.029s, table=87, n_packets=0, n_bytes=0, priority=650,nsi=255,nsp=5 actions=load:0x1100->NXM_NX_REG6[],resubmit(,220)
cookie=0xba5eba1100000201, duration=69.029s, table=87, n_packets=0, n_bytes=0, priority=650,nsi=254,nsp=5 actions=set_field:0->tun_id,output:1
cookie=0xba5eba1100000201, duration=68.999s, table=87, n_packets=0, n_bytes=0, priority=650,nsi=254,nsp=8388613 actions=load:0x1100->NXM_NX_REG6[],resubmit(,220)
cookie=0xba5eba1100000203, duration=68.996s, table=87, n_packets=0, n_bytes=0, priority=650,nsi=253,nsp=8388613 actions=pop_nsh,set_field:02:14:84:5e:a8:5d->eth_src,resubmit(,17)

An interesting scenario to show the Logical SFF strength is the migration of a SF from a compute node to another. The OpenDaylight will learn the new topology by itself, then it will re-render the new flows to the new SFFs affected.

Logical SFF - SF Migration Example

Logical SFF - SF Migration Example

In our example, SF2 is moved from Node4 to Node2 then OpenDaylight removes NSH specific flows from Node4 and puts them in Node2. Check below flows showing this effect. Now Node3 keeps holding the first SF of NSP 8388613 and the last SF of NSP 5; but Node2 becomes the new holder of the first SF of NSP 5 and the last SF of NSP 8388613.

Rendered Flows Node 3 After Migration

cookie=0x14, duration=64.044s, table=83, n_packets=0, n_bytes=0, priority=250,nsp=5 actions=goto_table:86
cookie=0x14, duration=63.947s, table=83, n_packets=0, n_bytes=0, priority=250,nsp=8388613 actions=goto_table:86
cookie=0x14, duration=64.044s, table=86, n_packets=0, n_bytes=0, priority=550,nsi=254,nsp=5 actions=load:0x8e0a37cc9094->NXM_NX_ENCAP_ETH_SRC[],load:0x6ee006b4c51e->NXM_NX_ENCAP_ETH_DST[],goto_table:87
cookie=0x14, duration=63.947s, table=86, n_packets=0, n_bytes=0, priority=550,nsi=255,nsp=8388613 actions=load:0x8e0a37cc9094->NXM_NX_ENCAP_ETH_SRC[],load:0x6ee006b4c51e->NXM_NX_ENCAP_ETH_DST[],goto_table:87
cookie=0xba5eba1100000201, duration=64.034s, table=87, n_packets=0, n_bytes=0, priority=650,nsi=254,nsp=5 actions=load:0x800->NXM_NX_REG6[],resubmit(,220)
cookie=0xba5eba1100000203, duration=64.034s, table=87, n_packets=0, n_bytes=0, priority=650,nsi=253,nsp=5 actions=pop_nsh,set_field:6e:e0:06:b4:c5:1e->eth_src,resubmit(,17)
cookie=0xba5eba1100000201, duration=63.947s, table=87, n_packets=0, n_bytes=0, priority=650,nsi=255,nsp=8388613 actions=load:0x800->NXM_NX_REG6[],resubmit(,220)
cookie=0xba5eba1100000201, duration=63.942s, table=87, n_packets=0, n_bytes=0, priority=650,nsi=254,nsp=8388613 actions=set_field:0->tun_id,output:2

Rendered Flows Node 2 After Migration

cookie=0x14, duration=56.856s, table=83, n_packets=0, n_bytes=0, priority=250,nsp=5 actions=goto_table:86
cookie=0x14, duration=56.755s, table=83, n_packets=0, n_bytes=0, priority=250,nsp=8388613 actions=goto_table:86
cookie=0x14, duration=56.847s, table=86, n_packets=0, n_bytes=0, priority=550,nsi=255,nsp=5 actions=load:0xbea93873f4fa->NXM_NX_ENCAP_ETH_SRC[],load:0x214845ea85d->NXM_NX_ENCAP_ETH_DST[],goto_table:87
cookie=0x14, duration=56.755s, table=86, n_packets=0, n_bytes=0, priority=550,nsi=254,nsp=8388613 actions=load:0xbea93873f4fa->NXM_NX_ENCAP_ETH_SRC[],load:0x214845ea85d->NXM_NX_ENCAP_ETH_DST[],goto_table:87
cookie=0xba5eba1100000201, duration=56.823s, table=87, n_packets=0, n_bytes=0, priority=650,nsi=255,nsp=5 actions=load:0x1100->NXM_NX_REG6[],resubmit(,220)
cookie=0xba5eba1100000201, duration=56.823s, table=87, n_packets=0, n_bytes=0, priority=650,nsi=254,nsp=5 actions=set_field:0->tun_id,output:4
cookie=0xba5eba1100000201, duration=56.755s, table=87, n_packets=0, n_bytes=0, priority=650,nsi=254,nsp=8388613 actions=load:0x1100->NXM_NX_REG6[],resubmit(,220)
cookie=0xba5eba1100000203, duration=56.750s, table=87, n_packets=0, n_bytes=0, priority=650,nsi=253,nsp=8388613 actions=pop_nsh,set_field:02:14:84:5e:a8:5d->eth_src,resubmit(,17)

Rendered Flows Node 4 After Migration

-- No flows for NSH processing --

Classifier impacts

As previously mentioned, in the Logical SFF rationale, the Logical SFF feature relies on Genius to get the dataplane IDs of the OpenFlow switches, in order to properly steer the traffic through the chain.

Since one of the classifier’s objectives is to steer the packets into the SFC domain, the classifier has to be aware of where the first Service Function is located - if it migrates somewhere else, the classifier table has to be updated accordingly, thus enabling the seemless migration of Service Functions.

For this feature, mobility of the client VM is out of scope, and should be managed by its high-availability module, or VNF manager.

Keep in mind that classification always occur in the compute-node where the client VM (i.e. traffic origin) is running.

How to attach the classifier to a Logical SFF

In order to leverage this functionality, the classifier has to be configured using a Logical SFF as an attachment-point, specifying within it the neutron port to classify.

The following examples show how to configure an ACL, and a classifier having a Logical SFF as an attachment-point:

Configure an ACL

The following ACL enables traffic intended for port 80 within the subnetwork 192.168.2.0/24, for RSP1 and RSP1-Reverse.

{
  "access-lists": {
    "acl": [
      {
        "acl-name": "ACL1",
        "acl-type": "ietf-access-control-list:ipv4-acl",
        "access-list-entries": {
          "ace": [
            {
              "rule-name": "ACE1",
              "actions": {
                "service-function-acl:rendered-service-path": "RSP1"
              },
              "matches": {
                "destination-ipv4-network": "192.168.2.0/24",
                "source-ipv4-network": "192.168.2.0/24",
                "protocol": "6",
                "source-port-range": {
                    "lower-port": 0
                },
                "destination-port-range": {
                    "lower-port": 80
                }
              }
            }
          ]
        }
      },
      {
        "acl-name": "ACL2",
        "acl-type": "ietf-access-control-list:ipv4-acl",
        "access-list-entries": {
          "ace": [
            {
              "rule-name": "ACE2",
              "actions": {
                "service-function-acl:rendered-service-path": "RSP1-Reverse"
              },
              "matches": {
                "destination-ipv4-network": "192.168.2.0/24",
                "source-ipv4-network": "192.168.2.0/24",
                "protocol": "6",
                "source-port-range": {
                    "lower-port": 80
                },
                "destination-port-range": {
                    "lower-port": 0
                }
              }
            }
          ]
        }
      }
    ]
  }
}
curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache"
--data '${JSON}' -X PUT --user
admin:admin http://localhost:8181/restconf/config/ietf-access-control-list:access-lists/

Configure a classifier JSON

The following JSON provisions a classifier, having a Logical SFF as an attachment point. The value of the field ‘interface’ is where you indicate the neutron ports of the VMs you want to classify.

{
  "service-function-classifiers": {
    "service-function-classifier": [
      {
        "name": "Classifier1",
        "scl-service-function-forwarder": [
          {
            "name": "sfflogical1",
            "interface": "09a78ba3-78ba-40f5-a3ea-1ce708367f2b"
          }
        ],
        "acl": {
            "name": "ACL1",
            "type": "ietf-access-control-list:ipv4-acl"
         }
      }
    ]
  }
}
curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache"
--data '${JSON}' -X PUT --user
admin:admin http://localhost:8181/restconf/config/service-function-classifier:service-function-classifiers/

SFC pipeline impacts

After binding SFC service with a particular interface by means of Genius, as explained in the Genius User Guide, the entry point in the SFC pipeline will be table 82 (SFC_TRANSPORT_CLASSIFIER_TABLE), and from that point, packet processing will be similar to the SFC OpenFlow pipeline, just with another set of specific tables for the SFC service.

This picture shows the SFC pipeline after service integration with Genius:

SFC Logical SFF OpenFlow pipeline

SFC Logical SFF OpenFlow pipeline

Directional data plane locators for symmetric paths

Overview

A symmetric path results from a Service Function Path with the symmetric field set or when any of the constituent Service Functions is set as bidirectional. Such a path is defined by two Rendered Service Paths where one of them steers the traffic through the same Service Functions as the other but in opposite order. These two Rendered Service Paths are also said to be symmetric to each other and gives to each path a sense of direction: The Rendered Service Path that corresponds to the same order of Service Functions as that defined on the Service Function Chain is tagged as the forward or up-link path, while the Rendered Service Path that corresponds to the opposite order is tagged as reverse or down-link path.

Directional data plane locators allow the use of different interfaces or interface details between the Service Function Forwarder and the Service Function in relation with the direction of the path for which they are being used. This function is relevant for Service Functions that would have no other way of discerning the direction of the traffic, like for example legacy bump-in-the-wire network devices.

                    +-----------------------------------------------+
                    |                                               |
                    |                                               |
                    |                      SF                       |
                    |                                               |
                    |  sf-forward-dpl                sf-reverse-dpl |
                    +--------+-----------------------------+--------+
                             |                             |
                     ^       |      +              +       |      ^
                     |       |      |              |       |      |
                     |       |      |              |       |      |
                     +       |      +              +       |      +
                Forward Path | Reverse Path   Forward Path | Reverse Path
                     +       |      +              +       |      +
                     |       |      |              |       |      |
                     |       |      |              |       |      |
                     |       |      |              |       |      |
                     +       |      v              v       |      +
                             |                             |
                 +-----------+-----------------------------------------+
  Forward Path   |     sff-forward-dpl               sff-reverse-dpl   |   Forward Path
+--------------> |                                                     | +-------------->
                 |                                                     |
                 |                         SFF                         |
                 |                                                     |
<--------------+ |                                                     | <--------------+
  Reverse Path   |                                                     |   Reverse Path
                 +-----------------------------------------------------+

As shown in the previous figure, the forward path egress from the Service Function Forwarder towards the Service Function is defined by the sff-forward-dpl and sf-forward-dpl data plane locators. The forward path ingress from the Service Function to the Service Function Forwarder is defined by the sf-reverse-dpl and sff-reverse-dpl data plane locators. For the reverse path, it’s the opposite: the sff-reverse-dpl and sf-reverse-dpl define the egress from the Service Function Forwarder to the Service Function, and the sf-forward-dpl and sff-forward-dpl define the ingress into the Service Function Forwarder from the Service Function.

Note

Directional data plane locators are only supported in combination with the SFC OF Renderer at this time.

Configuration

Directional data plane locators are configured within the service-function-forwarder in the service-function-dictionary entity, which describes the association between a Service Function Forwarder and Service Functions:

service-function-forwarder.yang
     list service-function-dictionary {
         key "name";
         leaf name {
           type sfc-common:sf-name;
           description
               "The name of the service function.";
         }
         container sff-sf-data-plane-locator {
           description
             "SFF and SF data plane locators to use when sending
              packets from this SFF to the associated SF";
           leaf sf-dpl-name {
             type sfc-common:sf-data-plane-locator-name;
             description
               "The SF data plane locator to use when sending
                packets to the associated service function.
                Used both as forward and reverse locators for
                paths of a symmetric chain.";
           }
           leaf sff-dpl-name {
             type sfc-common:sff-data-plane-locator-name;
             description
               "The SFF data plane locator to use when sending
                packets to the associated service function.
                Used both as forward and reverse locators for
                paths of a symmetric chain.";
           }
           leaf sf-forward-dpl-name {
             type sfc-common:sf-data-plane-locator-name;
             description
               "The SF data plane locator to use when sending
                packets to the associated service function
                on the forward path of a symmetric chain";
           }
           leaf sf-reverse-dpl-name {
             type sfc-common:sf-data-plane-locator-name;
             description
               "The SF data plane locator to use when sending
                packets to the associated service function
                on the reverse path of a symmetric chain";
           }
           leaf sff-forward-dpl-name {
             type sfc-common:sff-data-plane-locator-name;
             description
               "The SFF data plane locator to use when sending
                packets to the associated service function
                on the forward path of a symmetric chain.";
           }
           leaf sff-reverse-dpl-name {
             type sfc-common:sff-data-plane-locator-name;
             description
               "The SFF data plane locator to use when sending
                packets to the associated service function
                on the reverse path of a symmetric chain.";
           }
         }
     }

Example

The following configuration example is based on the Logical SFF configuration one. Only the Service Function and Service Function Forwarder configuration changes with respect to that example:

curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache"
--data '${JSON}' -X PUT --user
admin:admin http://localhost:8181/restconf/config/restconf/config/service-function:service-functions/

Service Functions JSON.

{
"service-functions": {
    "service-function": [
        {
            "name": "firewall-1",
            "type": "firewall",
            "sf-data-plane-locator": [
                {
                    "name": "sf-firewall-net-A-dpl",
                    "interface-name": "eccb57ae-5a2e-467f-823e-45d7bb2a6a9a",
                    "transport": "service-locator:mac",
                    "service-function-forwarder": "sfflogical1"

                },
                {
                    "name": "sf-firewall-net-B-dpl",
                    "interface-name": "7764b6f1-a5cd-46be-9201-78f917ddee1d",
                    "transport": "service-locator:mac",
                    "service-function-forwarder": "sfflogical1"

                }
            ]
        },
        {
            "name": "dpi-1",
            "type": "dpi",
            "sf-data-plane-locator": [
                {
                    "name": "sf-dpi-net-A-dpl",
                    "interface-name": "df15ac52-e8ef-4e9a-8340-ae0738aba0c0",
                    "transport": "service-locator:mac",
                    "service-function-forwarder": "sfflogical1"
                },
                {
                    "name": "sf-dpi-net-B-dpl",
                    "interface-name": "1bb09b01-422d-4ccf-8d7a-9ebf00d1a1a5",
                    "transport": "service-locator:mac",
                    "service-function-forwarder": "sfflogical1"
                }
            ]
        }
    ]
}
}
curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache"
--data '${JSON}' -X PUT --user
admin:admin http://localhost:8181/restconf/config/service-function-forwarder:service-function-forwarders/

Service Function Forwarders JSON.

{
"service-function-forwarders": {
    "service-function-forwarder": [
        {
            "name": "sfflogical1"
            "sff-data-plane-locator": [
                {
                    "name": "sff-firewall-net-A-dpl",
                    "data-plane-locator": {
                        "interface-name": "eccb57ae-5a2e-467f-823e-45d7bb2a6a9a",
                        "transport": "service-locator:mac"
                    }
                },
                {
                    "name": "sff-firewall-net-B-dpl",
                    "data-plane-locator": {
                        "interface-name": "7764b6f1-a5cd-46be-9201-78f917ddee1d",
                        "transport": "service-locator:mac"
                    }
                },
                {
                    "name": "sff-dpi-net-A-dpl",
                    "data-plane-locator": {
                        "interface-name": "df15ac52-e8ef-4e9a-8340-ae0738aba0c0",
                        "transport": "service-locator:mac"
                    }
                },
                {
                    "name": "sff-dpi-net-B-dpl",
                    "data-plane-locator": {
                        "interface-name": "1bb09b01-422d-4ccf-8d7a-9ebf00d1a1a5",
                        "transport": "service-locator:mac"
                    }
                }
            ],
            "service-function-dictionary": [
                {
                    "name": "firewall-1",
                    "sff-sf-data-plane-locator": {
                        "sf-forward-dpl-name": "sf-firewall-net-A-dpl",
                        "sf-reverse-dpl-name": "sf-firewall-net-B-dpl",
                        "sff-forward-dpl-name": "sff-firewall-net-A-dpl",
                        "sff-reverse-dpl-name": "sff-firewall-net-B-dpl",
                    }
                },
                {
                    "name": "dpi-1",
                    "sff-sf-data-plane-locator": {
                        "sf-forward-dpl-name": "sf-dpi-net-A-dpl",
                        "sf-reverse-dpl-name": "sf-dpi-net-B-dpl",
                        "sff-forward-dpl-name": "sff-dpi-net-A-dpl",
                        "sff-reverse-dpl-name": "sff-dpi-net-B-dpl",
                    }
                }
            ]
        }
    ]
}
}

In comparison with the Logical SFF example, noticed that each Service Function is configured with two data plane locators instead of one so that each can be used in different directions of the path. To specify which locator is used on which direction, the Service Function Forwarder configuration is also more extensive compared to the previous example.

When comparing this example with the Logical SFF one, that the Service Function Forwarder is configured with data plane locators and that they hold the same interface name values as the corresponding Service Function interfaces. This is because in the Logical SFF particular case, a single logical interface fully describes an attachment of a Service Function Forwarder to a Service Function on both the Service Function and Service Function Forwarder sides. For non-Logical SFF scenarios, it would be expected for the data plane locators to have different values as we have seen on other examples through out this user guide. For example, if mac addresses are to be specified in the locators, the Service Function would have a different mac address than the Service Function Forwarder.

As a result of the overall configuration, two Rendered Service Paths are implemented. The forward path:

                      +------------+                +-------+
                      | firewall-1 |                | dpi- 1 |
                      +---+---+----+                +--+--+-+
                          ^   |                        ^  |
                 net-A-dpl|   |net-B-dpl      net-A-dpl|  |net-B-dpl
                          |   |                        |  |
+----------+              |   |                        |  |             +----------+
| client A +--------------+   +------------------------+  +------------>+ server B |
+----------+                                                            +----------+

And the reverse path:

                      +------------+                +-------+
                      | firewall 1 |                | dpi-1 |
                      +---+---+----+                +--+--+-+
                          |   ^                        |  ^
                 net-A-dpl|   |net-B-dpl      net-A-dpl|  |net-B-dpl
                          |   |                        |  |
+----------+              |   |                        |  |             +----------+
| client A +<-------------+   +------------------------+  +-------------+ server B |
+----------+                                                            +----------+

Consider the following notes to put the example in context:

  • The classification function is obviated from the illustration.
  • The forward path is up-link traffic from a client in network A to a server in network B.
  • The reverse path is down-link traffic from a server in network B to a client in network A.
  • The service functions might be legacy bump-in-the-wire network devices that need to use different interfaces for each network.

SFC Statistics User Guide

Statistics can be queried for Rendered Service Paths created on OVS bridges. Future support will be added for Service Function Forwarders and Service Functions. Future support will also be added for VPP and IOs-XE devices.

To use SFC statistics the ‘odl-sfc-statistics’ Karaf feature needs to be installed.

Statistics are queried by sending an RPC RESTconf message to ODL. For RSPs, its possible to either query statistics for one individual RSP or for all RSPs, as follows:

Querying statistics for a specific RSP:

curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache"
--data '{ "input": { "name" : "path1-Path-42" } }' -X POST --user admin:admin
http://localhost:8181/restconf/operations/sfc-statistics-operations:get-rsp-statistics

Querying statistics for all RSPs:

curl -i -H "Content-Type: application/json" -H "Cache-Control: no-cache"
--data '{ "input": { } }' -X POST --user admin:admin
http://localhost:8181/restconf/operations/sfc-statistics-operations:get-rsp-statistics

The following is the sort of output that can be expected for each RSP.

{
    "output": {
        "statistics": [
            {
                "name": "sfc-path-1sf1sff-Path-34",
                "statistic-by-timestamp": [
                    {
                        "service-statistic": {
                            "bytes-in": 0,
                            "bytes-out": 0,
                            "packets-in": 0,
                            "packets-out": 0
                        },
                        "timestamp": 1518561500480
                    }
                ]
            }
        ]
    }
}