1. SFC description

The OPNFV SFC feature will create service chains, classifiers, and create VMs for Service Functions, allowing for client traffic intended to be sent to a server to first traverse the provisioned service chain.

The Service Chain creation consists of configuring the OpenDaylight SFC feature. This configuration will in-turn configure Service Function Forwarders to route traffic to Service Functions. A Service Function Forwarder in the context of OPNFV SFC is the “br-int” OVS bridge on an Open Stack compute node.

The classifier(s) consist of configuring the OpenDaylight Netvirt feature. Netvirt is a Neutron backend which handles the networking for VMs. Netvirt can also create simple classification rules (5-tuples) to send specific traffic to a pre-configured Service Chain. A common example of a classification rule would be to send all HTTP traffic (tcp port 80) to a pre-configured Service Chain.

Service Function VM creation is performed via a VNF Manager. Currently, OPNFV SFC is integrated with OpenStack Tacker, which in addition to being a VNF Manager, also orchestrates the SFC configuration. In OPNFV SFC Tacker creates service chains, classification rules, creates VMs in OpenStack for Service Functions, and then communicates the relevant configuration to OpenDaylight SFC.

2. SFC capabilities and usage

The OPNFV SFC feature can be deployed with either the “os-odl_l2-sfc-ha” or the “os-odl_l2-sfc-noha” scenario. SFC usage for both of these scenarios is the same.

As previously mentioned, Tacker is used as a VNF Manager and SFC Orchestrator. All the configuration necessary to create working service chains and classifiers can be performed using the Tacker command line. Refer to the Tacker walkthrough (step 3 and onwards) for more information.

2.1. SFC API usage guidelines and example

Refer to the Tacker walkthrough for Tacker usage guidelines and examples.