DATA PLANE LEARNING OF BI-DIRECTIONAL SERVICE CHAINS

摘要

Techniques are provided to decouple service chain structure from the underlying network forwarding state and allow for data plane learning of service chain forwarding requirements and any association between services function state requirements and the forward and reverse forwarding paths for a service chain. In a network comprising a plurality of network nodes each configured to apply a service function to traffic that passes through the respective network node, a packet is received at a network node. When the network node determines that the service function it applies is stateful, it updates context information in a network service header of the packet to indicate that the service function applied at the network node is stateful and that traffic for a reverse path matching the classification criteria is to be returned to the network node.

主权项

1. A method comprising:
receiving a packet at a network node of a service chain; determining that the network node is an exit point for the packet for the service chain based on location information in a header of the packet; identifying a stateful service function applied in the service chain based on context information in the header; recording classification criteria for forwarding return traffic into the service chain; and generating information defining a reverse path for the return traffic from the context information identifying the stateful service function.