RTP session identification is performed using libfindrtp. libfindrtp is a C library that identifies sessions between two endpoints by observing VoIP signaling traffic and watching for call set-up. Constraints can be passed to the library to limit session identification to a single endpoint, specific multiple endpoints, or even specific multiple endpoints using specific UDP ports. These constraints are passed through to libfindrtp from the input provided to the SteganRTP application via the command-line. At the time of this writing, libfindrtp supports session identification via the Session Initiation Protocol (SIP) and Cisco Skinny Call Control Protocol (SCCP) VoIP signaling protocols.