This CvSessionProtocol object specifies which session protocol was used to set up the Internet call between the local and remote router over the IP backbone. An administrator uses it to confirm whether calls are being signaled with the expected protocol (such as SIP or H.323), which matters when a network is being migrated between signaling protocols. For example, seeing an unexpected protocol value on calls to a newly migrated site would tell the admin the far-end router hasn't yet switched to the intended signaling protocol.