SIP is a protocol of growing importance, with uses for VoIP, instant messaging, presence, and more. However, its performance is not well-studied or understood. In this paper we experimentally evaluate SIP server performance using micro-benchmarks meant to capture common SIP server scenarios: registration, proxying, and redirection. We use standard open-source SIP software such as OpenSER and SIPp, running on an IBM Blade-Center with Red Hat Enterprise Linux with Gigabit Ethernet connectivity.
We show performance varies greatly depending on the server scenario and how the protocol is used. Depending on the configuration, throughput can vary from hundreds to thousands of operations per second. For example, we observe that the choice of stateless vs. stateful proxying, using TCP rather than UDP, or including MD5-based authentication can each can affect performance by a factor of 2-4. We also provide kernel and application profiles using Oprofile that help explain and illustrate processing costs. Finally, we provide a simple fix for transaction-stateful proxying that improves performance by a factor of 10.
By: Erich Nahum; John Tracey; Charles P. Wright
Published in: RC24183 in 2007
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