Technical data

ServerIron ADX Advanced Server Load Balancing Guide 1
53-1002435-03
Chapter
1
SIP Server Load Balancing
In this chapter
•SIP overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
•SIP SLB and call persistence using ServerIron ADX . . . . . . . . . . . . . . . . . . . . 6
•Configuring SIP SLB. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
•SIP SLB command reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
SIP overview
The Session Initiation Protocol (SIP) is a signaling protocol used by numerous IP communication
products to create session-oriented connections between two or more endpoints in an IP network.
SIP is emerging as the preferred technology for Voice over IP (VoIP) implementations.
Application-aware network switches play a vital role in increasing the uptime and availability of
IP-based services such as VoIP. Many customers rely on this technology to meet mission-critical
application requirements. Together with advanced SIP intelligence, ServerIron ADX switches offer a
highly scalable, available, and secure load balancing infrastructure for SIP applications.
SIP is an application-layer protocol that can establish, modify, and terminate multimedia sessions,
such as Internet telephony. In this implementation, ServerIron ADX SIP server load balancing
balances SIP requests and responses, based on a Call-ID.
SIP Server Load Balancing is based on a request-and-response transaction model that is similar to
HTTP. Each transaction consists of a request that invokes a particular method on the server, and at
least one response. The method is carried within the request message.
For more information, see SIP: Session Initiation Protocol - RFC 3261.