Image Processing Reference
At the very least, you should be wiring with a cabling system that is rated at
Category 5 (CAT-5). This is a specification of the quality of the cable, connectors, and other
You also need to ensure that the four pairs of wires in the unshielded twisted pair
(UTP) cable are wired correctly. There are two well-known formats, T568A and T568B.
They are different, for historical reasons having to do with legacy telephony systems. If
you mix telephone and Ethernet systems so they can share the same structured cabling, be
careful to keep them separate when you patch them or you will fry your Ethernet inter-
faces in any PC that is accidentally connected to the telephone network.
You must also be careful to use crossover cables only where appropriate. They are
normally used to join stackable hubs together. Crossover cables are occasionally useful
for connecting two Ethernet-equipped devices together. It's all you need to create a net-
work of just two nodes. Keep a crossover cable handy in your toolkit just in case you
Hubs or Switches?
Make sure that your network is connected together with switches—avoid the use of hubs.
Look at Figure 29-6 to see how all the traffic is directed along a common signal path inside
Contrast the way a hub works with the direct port-to-port connections inside a
switch. None of the traffic between two ports affects any other ports because there is no
shared signal path (see Figure 29-7).
Hubs present all the network traffic on all the ports. A switch connects one port
directly to another and bypasses all the others. The traffic is direct and private and does
not interfere with any of the traffic going between other port pairs. For video delivery,
this is very good.
One of the issues with video is that the data is bulky. Storing video requires a lot of space
to describe just a few seconds' worth of content. Moving the footage around your system
takes more time than you thought it would. Within the bounds of your own system, run
Figure 29-6 Network hub internals.