I would like to know whether there is some troubles using pairs 4/5 and 7/8 to transmit voice over a Cat 5 cable while it is transmitting data through another pairs (1/2 and 3/6). Is it operational and recommended?
I would like to know whether there is some troubles using pairs 4/5 and 7/8 to transmit voice over a Cat 5 cable while it is transmitting data through another pairs (1/2 and 3/6). Is it operational and recommended?
— Frederico Joca
You raise a very good point. On an analog phone or modem line, you can but I wouldnt recommend it. While you are not taking away from the active pairs 1/2 and 3/6, you are taking away from the wire pairs used for providing some shielding functionality to the active wire pairs.
At a small college I used to worked at, we did this from time to time when an analog phone line was needed in a area that we couldn’t justify the cost to install additional wiring for just the phone. With the signal levels you had on 10Base-T networks, you could do this and not really have to worry a lot about possible problems. As you start to work with 100Base-T – and especially 1000Base-T – having that additional wiring in place to help minimize the electrical noise or interference present in most work environments becomes even more important. If you have seen some of the ways that wiring has been run in some cases, right over the top or very near fluorescent light fixtures, you will want every advantage to keep from having problems with the network.
Even with the cost of copper today, you will still pay more as a general rule for the labor to pull the cable than you will for the actual cable itself. If you aren’t pulling your own wiring and use a contractor for this task, I think you will find that they wont charge much more for pulling an additional cable or two when they are pulling a run to where you need it. Even if you dont anticipate needing additional wiring today for either the network or another phone line, pulling an additional cabling can help you out of a problem down the road when you either need an additional network connection or develop a problem where nothing else has resolved the problem, being able to switch over to a “spare” cable can be to qoute the Mastercard commercial “priceless.”
