Hi, fellows. Some advice please. I'm asked to extend T-1/PRI ckts from time to time from the demarc to the suite. Since I was never trained on T-1 while in the telco, I'm not really comfortable with this. I know the customer's TX is on 5/4 and his RX is 2/1, but does individual polarity on the pairs matter? If I should reverse t-r on TX, for example, would that fail it? I hate to pronounce a circuit good without a T-Bert, which I don't have, either. I just have a wiremap tester.
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!
T-1 cabling
- Thread starter exverizon
- Start date
TouchToneTommy
Vendor
Polarity won't matter, but flipping Transmit and Receive certainly will. A loopback plug will show good even if the pairs are swapped.
Prepare for endless discussion on what type of cable and jack to use. Shielded, unshielded, two cables, one cable for all the transmits, another for all the receives, Cat-5, etc.
Prepare for endless discussion on what type of cable and jack to use. Shielded, unshielded, two cables, one cable for all the transmits, another for all the receives, Cat-5, etc.
If you are asked to do this fairly frequently why not do yourself a favor and pick a used T-1 tester on Ebay.
Fagettabout T-berds, they cost too much. Look for a Network Probe 7100 or a T-com unit and keep watching and you can g et a deal for less than $200!
Good luck
Fagettabout T-berds, they cost too much. Look for a Network Probe 7100 or a T-com unit and keep watching and you can g et a deal for less than $200!
Good luck
Adding an additional question to some one else's....
When extending T1's is this manor, what is the max. distance? I've found 650' on 22AWG Cat3. Any other guidelines? We're having our PBX relocated to the new data center/telco facility, and it just dawned on us that the connection to the demarc is going to go from 70ft to 700ft. Are we in trouble????
Justin T. Clausen
Physical Layer Implementation
California State University, Monterey Bay
When extending T1's is this manor, what is the max. distance? I've found 650' on 22AWG Cat3. Any other guidelines? We're having our PBX relocated to the new data center/telco facility, and it just dawned on us that the connection to the demarc is going to go from 70ft to 700ft. Are we in trouble????
Justin T. Clausen
Physical Layer Implementation
California State University, Monterey Bay
dagwoodsystems
Programmer
Justin-
700 feet shouldn't be any trouble--especially in light of hawks' "real world" accomplishments.
But you're right, traditionally the upper end of the extension is supposed to be 655 feet; after that, a T1 repeater may be introduced. But as I always say, your mileage may vary. Just make sure that the DTE/Equipment LBO (Line Build Out) parameter in the CSU is strapped to compensate for that distance. You'll be fine.
____________________________
Any sufficiently advanced technology is indistinguishable from Magix. --Arthur C. Clarke (imbellished).
700 feet shouldn't be any trouble--especially in light of hawks' "real world" accomplishments.
But you're right, traditionally the upper end of the extension is supposed to be 655 feet; after that, a T1 repeater may be introduced. But as I always say, your mileage may vary. Just make sure that the DTE/Equipment LBO (Line Build Out) parameter in the CSU is strapped to compensate for that distance. You'll be fine.
____________________________
Any sufficiently advanced technology is indistinguishable from Magix. --Arthur C. Clarke (imbellished).
Just to clarify what dagwoods is saying....
From the output of the CSU to the DSX device (e.g. PBX) is limited to (in theory) 655 feet. The CSU and PBX would both need to be set to the 655 foot setting.
From the Dmarc to the CSU is a much greyer area. In the case of real t-carrier there can be up to 3000 feet from the last repeater to the CSU. IN this case the CSU would be programmed for "0 dB" build out.
How far you can go is dependent on how the line was built - nowadays there is often an active device as part of the dmarc(HDSL or HDSL2 remote unit) in which case you should be able to go 3 kft from that.
As the say, your mileage may vary!
Good Luck
From the output of the CSU to the DSX device (e.g. PBX) is limited to (in theory) 655 feet. The CSU and PBX would both need to be set to the 655 foot setting.
From the Dmarc to the CSU is a much greyer area. In the case of real t-carrier there can be up to 3000 feet from the last repeater to the CSU. IN this case the CSU would be programmed for "0 dB" build out.
How far you can go is dependent on how the line was built - nowadays there is often an active device as part of the dmarc(HDSL or HDSL2 remote unit) in which case you should be able to go 3 kft from that.
As the say, your mileage may vary!
Good Luck
Thanks for the info! With my limited T1 experience, this has been helpful. But I want to through in another wrinkle, just to make sure I"m on the right page.
From my past dealings, I'm familiar with what's referred here to as the CSU. But, what if the dmarc comes right out of a fiber driven LightSpan? I know there is a shelf of equipment somewhere in the middle, but I'm not sure which is our T1 service for the PBX and which are the T1 data circuits for the cell companies and the other entities on campus. So in my estimation, our T1's come right out of the Lightspan? Does that make any difference? Does that move us into the 3000' neighborhood?
Again thanks!
Justin
Justin T. Clausen
Physical Layer Implementation
California State University, Monterey Bay
From my past dealings, I'm familiar with what's referred here to as the CSU. But, what if the dmarc comes right out of a fiber driven LightSpan? I know there is a shelf of equipment somewhere in the middle, but I'm not sure which is our T1 service for the PBX and which are the T1 data circuits for the cell companies and the other entities on campus. So in my estimation, our T1's come right out of the Lightspan? Does that make any difference? Does that move us into the 3000' neighborhood?
Again thanks!
Justin
Justin T. Clausen
Physical Layer Implementation
California State University, Monterey Bay
dagwoodsystems
Programmer
Lightspan is a company...not a hardware manufacturer, que no? Their termination happens to be fiber on the CO side and copper on the CPE side.
But we don't care particularly how it's delivered, we only care about how it's extended from the copper customer interface side, right? The Lightspan termination that you've described is probably just a smartjack, and you'll still need the FCC-required CSU or DSU after that, which means that what's been said up to this point still counts!
____________________________
Any sufficiently advanced technology is indistinguishable from Magix. --Arthur C. Clarke (imbellished).
But we don't care particularly how it's delivered, we only care about how it's extended from the copper customer interface side, right? The Lightspan termination that you've described is probably just a smartjack, and you'll still need the FCC-required CSU or DSU after that, which means that what's been said up to this point still counts!
____________________________
Any sufficiently advanced technology is indistinguishable from Magix. --Arthur C. Clarke (imbellished).
mikeydidit
IS-IT--Management
dagwoodsystems has you in the right direction. I have the same setup and BellSouth calls theirs a fiber mux. This converts your circuits from light across fiber to a digital signal for copper. You should have a smartjack on the back of the mux for every circuit. I have some of these working without any type of repeater working over 2000'. I would try it without first. If you have problems with the equipment then you may want to try some sort of repeater midspan.
Hell, there are no rules here - we're trying to accomplish something.
Thomas A. Edison
For the best response to a question, read faq690-6594
Hell, there are no rules here - we're trying to accomplish something.
Thomas A. Edison
For the best response to a question, read faq690-6594
- Status
Similar threads
- Locked
- Question