Introduction

Why is a network drawn as a cloud? Is it because most are unaware of the processes happening as data tranverses the network?

In all but the smallest of enterprises, the IT department maintains the computer network infrastructure. How many of us are concerned with what happens beyond the RJ-45 jack on the wall? It says a lot for computer networks that we often forget the network is there. We haul files across the world at the click of a mouse, and they arrive seconds later.

With video media, things are different; we place many more demands on the network. So it helps to understand a little more about the data network, and the telecommunications infrastructure that underpins it.

The first thing that is different about the delivery of multimedia streams is that usually they do not use the universal TCP/IP (Transport Control Protocol over Internet Protocol). Second, the media files are very large compared with the average e-mail message or web page. Third, delivery in real-time is a prerequisite for smooth playback of video and audio.

A new set of network protocols has been developed to support multimedia streaming. As an example, advances in Internet protocols now support multi-casting, where one media stream serves hundreds or thousands of players. This is a handy facility for optimizing network resources if you want to webcast live to large audiences.

The media files are streamed over the general telecommunications network. Again, this is something we rarely think about, unless your...