The handoff point of any IP-enabled infrastructure. This is where a session passes from one network to another and can be defined as the edge of a carrier's network or the point between an enterprise and its carrier.
Network World: Session controller A session controller provides services between H.323 and SIP endpoints. In effect, this hardware/software combination operates simultaneously as an H.323 gatekeeper and SIP proxy server. In addition, it provides the SIP/H.323 interworking function that enables any-to-any connectivity between endpoints.
Quick Reference: Internet Telephony Internet telephony can be basically broken down into three categories consisting of PC-to-PC telephony, PC to Phone, and Phone to Phone.
