Additional sections:
The SBC functions as a Back-to-Back User Agent (B2B UA) when processing Path and Service route headers in REGISTER messages, and when using information derived from Path and Service-Route headers received in 200-class responses to REGISTER requests in outgoing INVITE messages. A B2B UA performs hop-by-hop routing rather than end-to-end routing. Each component of the network will only store the information of its nearest neighbor or next hop. For the purpose of Path and Service-Route Headers, this means only storing a single instance of each of those headers.
To process Path and Service-Route Headers, appropriate provisioning of ingress and egress IP Trunk Groups from the IP Signaling Profile screen is required.