Configuring SRv6 service chains
About SRv6 service chains
To meet service security and stability requirements, you can steer data packets to pass through various service nodes as orchestrated in the network. For example, steer data packets to pass through firewalls, IPSs, application accelerators, and NAT devices. SRv6 service function chaining
(SFC) is a technology that can meet the requirements. This technology adds SRv6 path information to the original packets to steer the packets to pass through application service devices as orchestrated. The path orchestrated by SRv6 SFC is called an SRv6 service chain.
SRv6 service chain basic concepts
As shown in Figure 89 , specific service packets from the user network are steered into the
application service nodes in the SRv6 service chain network. After the service nodes process the packets, the packets are forwarded to the destination.
Figure 89 SRv6 service chain network diagram
SF 1 SF 2
User network User network
SC SFF 1 SFF 2
SRv6-TE Policy
Tail node
SRv6 service chain network
An SRv6 service chain network contains the following components:
•
Service classifier (SC) —Source node of the SRv6 service chain, which is located at the edge of the SRv6 service chain network. The SC can use multiple methods to steer service data to an
SRv6 TE policy tunnel.
•
Service function (SF) —Node that provides specific application services for data traffic. An application service node that cannot recognize SRv6 packets is called an SRv6-unaware SF.
An application service node that can recognize SRv6 packets is called an SRv6-aware SF.
•
Service function forwarder (SFF) —Node that acts as a service chain proxy for SFs. Based on the SRv6 decapsulation information of received packets, the SFF forwards the packets to the
SFs associated with the SFF. The SFs process the packets, and then return the packets back to the SFF. The SFF determines whether to continue forwarding the packets.
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