Redirect Server (RS)

Redirect Server (RS)

  • receives SIP REGISTER messages from User Agents (UAs)
  • keeps track of registered users and their locations (i.e., registrations)
  • provides routing information for SIP INVITE messages
    • based on caller, callee, and registration information (for either or both parties)
    • based on where the INVITE message has already been
  • Supports redundancy
    • Utilizes multicast heartbeat
      • starts by listening for 2s for another RS
      • if found, then it synchronizes with this RS and will act as a redundant backup RS (following synchronization)
      • if not found, then it starts transmitting its own heartbeat
    • a given RS must mirror REGISTER messages (received from the MS) to the other RSs

Transcript

[slide523] They had a redirect server.