Capacity Measurement of IP-Multimedia Subsystem (IMS) Controllers

Measuring the capacity of the IP Multimedia Subsystem (IMS) controllers is very important due to the critical role it plays in the Next Generation Network (NGN) of the Fixed and Mobile Networks. This paper proposes a robust and scalable method that can be used to measure the capacity of the IMS controllers, Call Session Control Function (CSCF) and benchmark their different vendors. The purpose of this method is to measure the capacity of the server in terms of how many sessions or calls are routable into a defined time interval and what the consequences of overloading the system are. These issues are studied experimentally, using Open SIP Express Router (OpenSER), a high performance open source SIP server and SIPp, the de-facto standard for SIP performance benchmarking. It also provides the test results for Open SIP Express Router (OpenSER).