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Distance for 25 pair??

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ebyland

Technical User
Apr 6, 2004
4
US
Cat5 is good up to about 100 meters, what is the distance that 25 pair is good for?
 
We will be using both data and voice on the 25 pair. We're trying to decide if we should cat 5's or just one 25 pair. Would it cause problems to have voice and data together on the 25 pair?
 
Something to consider, if you try to run data on a high pair count cable (anything over 4 pair) you can not certify it. Personally I would only use 4 pair for data when using copper.
Tell me more about what you are trying to do.
Is this backbone or to a workstation?

Richard S. Anderson, RCDD
 
We're setting up a satellite office (inside a building with multiple offices) that is 270 feet away from the wiring closet. To start we'll have 3 workstations and 4 phone lines. At most we'll probably have about 5 workstations with phones in that office. We're just comparing the cost of 25 pair Vs. multiple runs of Cat5, but if the 25 pair is going to be problematic, then we'll stick to Cat5.
 
Not a problem for voice, but you are pushing the limits on length for data.
Sounds like you might be a candidate for fiber and a switch in the new area. i.e. run fiber from the existing TR to the new area, place a switch there and run 4 pair from there to each workstation. Thats rather simplistic but should give you the idea.

Richard S. Anderson, RCDD
 
The last time I checked the cost of 25 pair Cat5 plenum was higher than running 6 cat 5 plenum cables ,I guess it was so high due to supply and demand ,If plenum is not required maybe it is cheaper.The fiber solution is the ultimate,but if cost is an issue why not run a Cat 5 from switch to switch ,I guess it is all an issue of Data Transmission requirements.
 
The ultimate:

Run 1 25-pair for voice only, 1 Cat6 to run from existing TR switch to new switch, 1 fiber 6strand MM fiber unterminated for later use.

As stated earlier, a switch in the remote area would be a good route. But if a fiber switch is out of the question now, cat6 will work. But the fiber cable will probably be cheeper to buy, so install it now with everything else, and save the pennies to get the fiber switch later.

Justin T. Clausen
Physical Layer Implementation
California State University, Monterey Bay
 
actually you dont need a fiber switch you can use media convertors and a standard switch.

if you can't terminate the fiber yourself you can either run it and have someone else come terminate it or you can order a custom lenght pre-terminated and tested.

I would run cat 3 25 pair for voice and either two 5e or 6
4 pairs from your present closet to the new location then run as many 4 pair drops as needed in the satilite office.
 
Media converters aren't really neccesary with any up to date switch that has a modular slot for some type of uplink media. Most nortel switches, and some cisco switches have this, allowing you to put in at least 1 fiber pair (tx/rx).

I would go with Justin or Servamatic's route, depending on cash availability. You don't really want to go above 300 feet with a Cat5e or Cat6 run. I'm sure it would work, but why risk it?

If you can honestly say that from switch connection to switch connection (patch cords INCLUDED) that it will be 270 feet, then go for it. Even 280, 290, or 300, but I wouldn't go above that. Spec is a little higher I think, 320 something? I can't remember. I could be wrong.

I would certainly do copper if costs are important here. I would pull 2 cat5E or cat6 backbone cables (mind you, I say two just to have one for backup in case you have any problems, it's a real pain to refish that stuff in after it's all said and done). And I would also pull in at least 1 25 pair. Some digital phones in today's phone system world still use 2 pairs, which gives you a realisic capacity of only 12 sets. Depending on your future vision for this building, and also if any fax machines are involved, etc, I might pull a 50 pair (or two 25's) and a few network drops as well.

Just forward thinking.
 
Permanent link distance is 295 ft.
Channel is 328 ft.
Channel includes patch cords, Permanent Link is only the permanently installed cable.


Richard S. Anderson, RCDD
 
1. Mixing high speed (data) and low speed (voice) signals in the same jacket (25 pr) is not a good idea. ATT tried it with their Zone Wiring and it was not successful (in my opinion only). If you must, you can take the pair furthest apart in the 25pr for voice - data setup but it may not be worth the trouble.
2. If the cable(s) are going to be in a underground conduit, PVC cable stands up better than Plenum if subjected to moisture. Water block cable is best.
3. If you don't have the conduit running contiguosly end-to-end, you may need to terminate the water-block (gel filled) cable within 50' of first entry room and then transistion to code compliant cable to your end location.

Regards
Peter Buitenhek
Profit Developer.com
 
cat 5 , cannon suggest no more than 105m , 25 pair 90m would be pushing it
 
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