SFC Proxy Port Correlation for Non-Transparent Service Functions

This blueprint describes the support for non-transparent Service Functions in SFC Port Chains using SFC Proxy Port correlation.
Most legacy Service Functions (SF) do not support SFC (NSH) encapsulation, and require the SFC Proxy to re-classify each packet that is returned from the egress port of the SF. In addition, non-transparent SFs may make dynamic changes to the N-tuple of the packet header so it cannot be used for re-classification.

A solution is to use multiple instances of a non-transparent SF and assign the port-pair for each SF instance to a separate Port Chain.

SFC Proxy Port Pair Group is configured to operate as a Port Pair Correlation Map which maps each Port Chain to specific port-pair that represents each SF instance.