Nortel 3902 to Cat 5

[ianlawuk]

Hi Guys

I have a working 3902 in an office, connected directly from the back of the phone to the RJ45 socket on the wall. OK no probs!

If I take this phone with cable into the comms room where we have the TJF Krone frames, And punch a pair of copper into the TN on the frame and the other end punched down onto pins 4 and 5 of an RJ 45 socket, then plug the phone in, it doesn't work - nothing at all - totally dead.

In theory it should be the same as in the office... I must be missing something staring me in the face..

Any advice greatly appreciated... in advance!!

 

[scotthdiv]

You sure it's a 3902? If it's an RJ45, it's most likely an IP phone - probably a 2002.

 

[DFKSydney]

Did you try reversing the termination at the comms room end??????

 

[ianlawuk]

Its definitely a 3902 as we have many of these, its common place in our building, so not an IP phone, and as I say we do have it working in the office.

DKF: I have mate, first thing i tried, reversing the wires to the pins.

All logic says this should be working,

I've been working in this arena for 15 years now... but mostly with the older M3820 / 2616s, so unsure if its something with these 3902s that i'm not aware of. But wiring is wiring...

 

[derbydave]

Pins 4 & 5 are for analogue, digital phones use pins 1 & 2.

 

[norstarboy125]

3900 series phones are digital and don't have rj 45 inputs just rj 11. I'm sure the phone is marked with the proper set type underneath, you may want to give it another whirl. Or if set type is right then you may want to flip your cross connect at the frame, these phones are polarity sensitive.

Jeremy J. Carter
Charm City Communications

http://www.charmcitycommunications.com

Norstar. BCM. CS1000 Programmer

 

[PERRYPJ]

Is the TN on the MDF the same TN that's in the opffice or is another TN

OLD ROLMEN WORKING ON NORTELS AND AVAYA

 

[ianlawuk]

Guys

The issue was related to different structure cabling within the building, with different outlets etc having different pin combos. Nightmare.

Finally worked out I needed a straight through RJ 11 to RJ45 phone cable, whereas the one I was using for testimng had crossed pairs.

 

[NortelGuy1979]

A standard RJ11-11 line cord, with crossed tip & ring, will work just fine in an RJ45 jack. Tip & ring are to be crossed on standard silver-satin cords, including for Aries and Taurus sets.

Matthew - Technical Support Engineer Sr.

http://www.linkedin.com/in/matty79

 

[nessman]

Ah... nothing like non-standard wiring and jacks. Bottom line is phone systems are nothing more than a big game of connect the dots. If the lines aren't connecting the right dots, the phones don't work. Simple as that.

I cringe when I see termination blocks other than 66 or BIX used in telco apps (Krone blocks are usually found on Verizon demarcs in these parts and 110 blocks - while not common aren't unheard of either - they're just more of a pain when it comes to testing on the frame), and RJ-45 jacks used instead of RJ-11's.