SIP is a signalling protocol designed to create, modify, and terminate a multimedia session over the Internet Protocol. It is an application layer protocol that incorporates many elements of the Hypertext Transfer Protocol (HTTP) and the Simple Mail Transfer Protocol (SMTP). This tutorial covers most of the topics required for a basic understanding of SIP and to get a feel of how it works. Before proceeding with this tutorial, you should have a good grasp over preliminary networking concepts including some of the basic protocols such as TCP, UDP, HTTP, SMTP, and VoIP.
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Official DVSA Theory Test Kit Free
Contains ALL the information you need to pass your car theory test first time.