Streaming - A Practical Guide to Video and Audio Compression - page 360

One client

One client

Server process

One client

Edge server

Master server Fast, fat,

proprietary pipe
joining all edge
servers together.

Edge server

The Internet

Edge server

One client

Edge server

Edge server

One client

One client

One client

One client

Figure 20-6 Edge-serving model.

streamed content. These are the two principal companies that provide this capability. They
operate with slightly different emphases, and you may find that one or the other fits your
requirements better.

20.12.1 Akamai

Akamai has developed a very large infrastructure around the world. Some thousands of
Akamai servers have been deployed into the data centers run by the various ISP compa-
nies. Akamai has then connected all of its machines together with its own private network
that runs extremely quickly. Because it is Akamai's own network, it controls all of the
traffic and essentially has encircled the globe and connected its servers to a very large and
fast ring.
As soon as an end user hits an Akamai server for a file or stream, that edge server
checks the local repository; if the file does not exist, it requests a copy from the central
store. This is delivered so quickly that it does not hold up the download to the end user