5.1 Why Do We Need Standards for VoIP?

This chapter aims to explore what standards are, why they are required for realising voice over IP (VoIP), and how they are created. The trite answer to why we need standards for VoIP is that it is based upon IP and IP is a standard and so you cannot have VoIP without it. However, there are numerous, and potentially less obvious, reasons why standards are essential to VoIP. Some of these are a consequence of the natural separation of transport and application that occurs in VoIP systems; others derive from the establishment of any voice service, especially one that crosses the boundaries between the domains of different service or network providers and so encounters differences in administrative policy in other words, the real world is much more complex than the laboratory bench.

While a service is operating in your domain, you can control it, accepting the normal expectations of occasional failures of the technology. However, as soon as it leaves your domain, control passes to the service provider that owns the domain to which the service has passed. So for example, a voice call from the UK to Australia will cross from the UK domain to the Australian domain at some point, and the Australian domain will have control over parts of that call.

So that the Australian domain can handle the call correctly, it has to be able to accept it and understand what...