SIP persistence

Session Initiation Protocol is an application-layer protocol that manages sessions consisting of multiple participants, thus enabling real-time messaging, voice, data, and video. A session can be a simple two-way telephone call or Instant Message dialogue, or a complex, collaborative, multi-media conference call that includes voice, data, and video. With SIP, applications can communicate with one another by exchanging messages through the SCTP, TCP or UDP protocols.
SIP persistence is a type of persistence available for server pools. You can configure SIP persistence for proxy servers that receive SIP messages sent through the UDP profile. Local Traffic Manager currently supports persistence for SIP messages sent through the UDP, TCP, or SCTP protocols.