A demand-driven parsing method for SIP offload in home network

The session initiation protocol (SIP) is widely used as the signaling protocol for various services in the ubiquitous environment of the home network. SIP is a text-based protocol with characteristics of unordered and verbose headers, variable-size message, case-insensitive keyword etc., which imposes challenges for an efficient message processing. Thus, the ability to process SIP messages quickly is critical for the performance of consumer electronic devices, such as SIP phone and the home gateway in the home network. In this paper, a thorough analysis of the SIP message processing reveals that parsing messages entirely is the bottleneck of a SIP server performance. To solve this problem, a demand-driven parsing method (DPM) for home devices is introduced, which only parses some parts of the entire SIP message. We implement the DPM in a home gateway which acts as a high performance SIP server in the home network. Measurements show that the demand-driven parsing for SIP message can indeed decrease processing time.