Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations SkipVought on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

cat 5 cable for a VOIP system 1

Status
Not open for further replies.

NiceRing

Vendor
Jan 13, 2012
349
0
0
US
Would you ever install a VOIP system on cat5 not cat5e cabling??
 
100 meg ethernet is plenty fast for voice.
Distance is the same. 100 meters or 328 feet.
 
Yup, I've even done it over Cat3

Now, if you want to put a PC behind the phone on the same cable, that answer might change.

**********************************************
What's most important is that you realise ... There is no spoon.
 
Thanks for the feedback. It just seems like VOIP can be so flaky, I thought it might just add more problems.
 
If you have quality PoE switches and they are setup correctly. VOIP can be rock solid.
 
CAT5 is fine for VoIP. True 4 pair CAT3 is getting harder to find. Manufacturers, like Commscope, now take CAT5 cable that fails testing and labels & sells it as CAT3.

I [love2] "FEATURE 00"
 
company called phybridge can do up to 300mbps POE on cat3 for up to 1000 feet. Weve used it multiple times without issue. The new yorker hotel using it with mitel system and IP phones

 
I know one time I worked on a job where the run from the router to the computer was over 500'.
It was cat3 UG cable with only 2 pair terminated on the RJ45 keystone jack and they were able to get online with no problems. Couldn't believe it.
 
The 100 meter distance is just a specification that a cable cannot exceed this distance and be considered a CAT5 cable. I am sure we all have seen cases where cables much longer than this will appear to work OK. Especially if not trying to utilize any streaming or other bandwidth intensive apps like VoIP or video.

One interesting trouble ticket I had was a case where a handful of IP phones would not show the Message Waiting Indicator when a message was left. The IT person had followed their own color code instead of 568A or 568B. I commented that these phones, which happened to be on the longer runs, were possibly not working properly because the standard was not adhered to.

The IT person became most upset at this suggestion and insisted that color codes were not important. As long as Side A and Side B were the same, the cable would work. I replied that while that would be true in the case of continuity, the cable could not be considered CAT5E because the standard was not followed. It would certainly fail a certification attempt. I removed the jacket from the cable and showed him how each pair had a different twist rate. I further explained this was engineered for noise rejection and to offer the maximum bandwidth capability, particularly at the greater distances that the specification called for.

If anything, he became more upset because this would mean reterminating both ends of the cables. There were around 100 cables or so. I eventually asked him to stop calling me on this issue. I would no longer troubleshoot until the cabling was corrected as I had already eliminated all other causes that I could think of.

So, in a huff, he told me he was going to redo all the cabling to 568B and that "it had better work". I am not sure what the implied threat was but I do know that as of that first Monday morning after the rework, ALL the message waiting indicators worked flawlessly.

He also paid more consideration to my opinions on the phone system and cabling in general not to mention the bill for my troubleshooting... :)

Then there was the time in a Network Plus class where the instructor stated the color code "did not really matter as long as it is the same on both ends....", but that is a tale for another day.
 
And all IT had to do was let Telecom techs do telecom things.

Switches these days also help out that old cabling along.



________________________________________

Add me to LinkedIN

**New Allworx Forum**

small-logo-sig.png

=----(((((((((()----=
Toronto, CAN
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top