Mechanisms for using nat at a session border controller

Abstract

Disclosed are apparatus and methods for managing session data in a session border controller (SBC), where the session data is sent from a first node, such as a first phone, to a second node, such as a registrar or second phone. In general, embodiments of the present invention support SBC functionality by managing sessions through the SBC without implementing a terminate and regenerate of the sessions, but rather by intercepting packets destined to the second node and efficiently handling such functionality in the forwarding-path. Also in deployments where the endnodes require NAT (network address translation), mechanisms are provided in the SBC to perform NAT on the addresses embedded in the payload of the session data. In other aspects, mechanisms for keeping the sessions or NAT entries alive are facilitated at the SBC, even when an endnode has a expiration time that differs an expiration time of another device, such as a registar device. Other embodiments allow the actual media packets to flow through the SBC (e.g., for security, accounting, etc) while allowing two endnodes to utilize a same private address or domain.