VoIP Essentials

In this part . . . provide the information necessary to grasp VoIP, its structure, its myth, and the supporting elements that make it great. VoIP transmissions are not built like a normal phone call, and the unique nature of their design lend themselves to possibilities, both good and bad, that aren’t available with traditional telephony.
The process for Local Number Portability (LNP) in which phone numbers are migrated from traditional local carriers to VoIP carriers is covered in detail. The process, as well as the structure of the VoIP market is addressed to illuminate the challenges with this, seemingly simple task.
The specifics of the SIP and SDP elements of a VoIP transmission are dissected, revealing their functions and the expected banter between both ends of a VoIP call. Almost every aspect of a VoIP call is negotiated between the end points, and sometimes intermediary proxy servers, so great care was given to define the aspects of the communication so any issues can be identified.
This section finishes with an overview of a dial plan, the software of a VoIP phone system governing the routing of calls and deployment of applications. Aspects of it are covered for cost savings, useful features, and to identify the wealth of options available with a standard VoIP phone system.