Request Routing
So that requests addressed to the corresponding registered contact are routed to the proxy, the Oracle® Enterprise Session Border Controller includes the intervening proxy (i.e., the top Via) in the routing information for the registration cache when you set reg-via-proxy. To carry out this routing scheme, the system adds a Path header (if none is present) to the REGISTER. But it removes the Path header prior to sending the REGISTER to the registrar.
Note that when the received REGISTER contains a Path header, the Oracle® Enterprise Session Border Controller uses it for routing requests toward the endpoint and includes it in the forwarded REGISTER request—as is the case when you do not enable SIP registration via proxy.