You are here: CSP Developer’s Guide: Internet Protocol > 5 Session-Initiation Protocol (SIP) Software > SIP User Agent Redundancy
Overview
The SIP software supports redundancy allowing the SIP UA to continue functioning after a CSP Matrix Series 3 Card switchover.
In an CSP with redundant CSP Matrix Series 3 Cards, the cards themselves are physically identical.
Important! To enable SIP UA Redundancy, you must configure a shared IP address. The shared IP address is for redundancy only. All API message should be sent directly to the active matrix card’s IP address - not to the shared IP address.
Description
All communication to the CSP Matrix Series 3 Cards are over this one shared IP address. You create this shared IP configuration using DHCP or BOOTP. See Redundant CSP Matrix Series 3 Card in the API Developer’s Guide: Overview for general information about redundancy on the CSP Matrix Series 3 Card.
The two matrix cards communicate with each other over a High-Level Data Link Control (HDLC) link. The SIP software data structures are dynamically updated from the active CSP Matrix Series 3 Card to the standby CSP Matrix Series 3 Card on this midplane bus so calls in the connected or answered state are maintained during a switchover. Calls in transition are dropped.
Figure 5-4 SIP UA Redundancy
Configuring
See either of the following two procedures in the Application Development chapter of the Developer’s Guide: Overview to set up the shared IP address:
Configuring a Shared IP Address Using BOOTP Server
Configuring a Shared IP Address Using DHCP Server