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Connect a TN556 port to two ISDN phones?

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electronbee

Technical User
Nov 16, 2009
15
US
1) I am a newbie
2) I have been searching and have fond devices like the ADTRAN NT1 ACE which can convert a 2-wire U-Interface into two 4-wire BRI S/T interfaces. Is there a product that can do the same with the TN556 cards which are 4-wire? It'd be great if I could use both channels for individual phones.

Thanks!

eb
 
Page 11

BRI Terminating Resistor
The resistors balance the cable plant between the receiver and the transmitter
on the interface. When using the TN2198 ISDN-BRI 2-Wire U Interface circuit
pack, an NT1 is required. A terminating resistor is always required near the
terminal when the BRI S-type interface circuit pack (TN556 BRI 4-Wire S-NT Line
circuit pack) is used (see #5ESS Switch Integrated Services Digital Network
Customer

Premises Planning Guide, 533-700-100).
The resistor is built into the NT1 and can be 1 of 3 values, depending on the
configuration and the distance from the NT1 to the ISDN terminal. The resistor
value is controlled from the NT1. A terminating resistor adapter may be needed
near the terminal and can be placed in the satellite closet or work location.
NOTE:
The 440A4 terminating resistor and 110RA1-12 terminating resistor block
are UL listed. Most new installations are the 110RA1-12 terminating resistor
block. The following installation instructions should be observed.

- Never install telephone wiring during a lightning storm.
- Never install telephone jacks in wet locations unless the jack is specifically
designed for wet locations.
- Never touch uninsulated wires or terminals unless the telephone line has
been disconnected at the network interface.
- Use caution when installing or modifying telephone lines.


A great teacher, does not provide answers, but methods to teach others "How and where to find the answers"

bsh

35 years Bell, AT&T, Lucent, Avaya
Tier 3 for 25 years and counting
 
OK,

I am aware of the two types interfaces and termination. In fact, we have ONE 2198 card... unfortunately.

What I want is the ability to have two phones off of one port of a TN556 card. Since, I have two data channels I should be able to have two phones. I have also seen devices, and, I am sure the Definity supports this, which allow up to 8 phones with at most two being active. That is what I am looking for.

But, all of the devices that I have seen use the 2-wire U-interface.
 
Oops, I meant to say that I have two B-Channels and one D-Channel and the TN556 supports multipoint so I should be able to have 24 devices per card.

But, how?
 
7500 type data modules are 4 wire
7500 type voice terminals are 4-wire
7505D, 7506D, 7507D

8500 type data modules are 2 wire
8500 type voice terminalas are 2 wire with NT1 built into the terminal. Flip a switch on the bottom of the phone.
8503D, 8510T, 8520T

program a station xxxx with port 1a0401 with terminating resistor and a 7507 voice terminal.
program a station yyyy with port 1a0401 without terminating resistor and 7507 voice terminal.

both voice terminals will connect to the same circuit on the same tn556. One will need a terminating resistor in-line with the wiring from the port to the voice terminal.

A great teacher, does not provide answers, but methods to teach others "How and where to find the answers"

bsh

35 years Bell, AT&T, Lucent, Avaya
Tier 3 for 25 years and counting
 
Is that why some of my phones have a switch on the bottom for S/T or 100 ohm?

Any ways, I have Tone Commanders and AT&T 8510's but it seems possible and really easy now. I mean, really easy.

Thanks!

eb
 
multipoint means 1 "D" and 2 "B"

two stations, with two voice terminals on one port
or
one station with one data-module on one port

The link to the first document that I posted has all of the external terminating resistors you can use and how to wire them starting on page 11.


A great teacher, does not provide answers, but methods to teach others "How and where to find the answers"

bsh

35 years Bell, AT&T, Lucent, Avaya
Tier 3 for 25 years and counting
 
I ordered two 440A resistor filter from Westek. I hope its the right model since one Avaya document referenced a 440A and another a 440A4. Any ways, I will make a "splitter" (pg 5-62) similar to the BR851-B since it seems super simple. This should allow me to connect the two phones once I have assigned two extensions to one port, correct?

You mention using terminating resistors on one and not the other. But, the way Avaya lists it in their manual (provided by the pdf.textfiles link above) it seems I use the 440A4 (pg 5-59) or the 110RA1-12 (pg 5-60) terminating resistor block and then I go!

For my switch I use the Avaya Site Administration program, and then I start GEDI. Say I display two stations, can I just enter in the port number for both, or, is their a specific command/procedure to enable two extension on one port to exist? That what it seems like what you have listed above. Most people seem to copy/paste from a terminal program...

I appreciate your help AvayaTier3...

eb
 
same port will be programmed to each station
2 max on one port



A great teacher, does not provide answers, but methods to teach others "How and where to find the answers"

bsh

35 years Bell, AT&T, Lucent, Avaya
Tier 3 for 25 years and counting
 
The link to the first document that I posted has all of the external terminating resistors you can use and how to wire them starting on page 11.
Did you read this????

you would need 12 each, local to the voice terminals or
110RA1-12 terminating resistor block provides the 100 Ohm resistance for 12 lines.


Terminating Resistor
The terminating resistor reduces transmission reflections on the T-interface. In most cases, both
ends of the T-interface require a resistor; Basic MultiPoint is the exception.
Note: This document does not cover MultiPoint installation. For more information about
MultiPoint, see the Customer Premises Planning Guide, 533-700-100.
Consider the following information about terminating resistors:
- The T-card in the switch incorporates a 100 Ohm terminating resistor.
- The T-interface portion of the NT1 includes three options: 50 Ohms, 100 Ohms and High
Impedance (>2000 Ohms).
d The 8500-Series terminals support a 100 Ohm or High Impedance option. All other
AT&T terminals appear as High Impedance.
- The 440A4 terminating resistor adapter for use at the set is 100 Ohms.
- The 110RA1-12 terminating resistor block provides the 100 Ohm resistance for 12 lines.
Note: High Impedance acts like an open circuit, preventing the receiver from reducing
transmission efficiency. The 100 Ohm resistances balance the transmission path,
improving signal recognition in the receiver.
Remember the following in selecting 100 Ohm, 50 Ohm, or High Impedance in the NT1:
- Selecting the 100 Ohm option in the NT1 requires a 100 Ohm resistance in the transmission
path. For single terminal interfaces, the best transmission results when the 440A4
terminating resistor adapter is placed near the set. For uniform procedures, install the
440A4 at the information outlet. When using the 440A4, ISDN terminals should be High
Impedance. The 8503T may be optioned for 100 Ohms, but in this case, do not use the
440A4. For Branched MultiPoint, use the 110RA1-12 to provide the 100 Ohm termination
before the branch.
- Select the 50 Ohm option when the NT1 is installed in an office with the ISDN station or
when the NT1 will be rack-mounted less than 250 cable feet (24 gauge DIW) from the
ISDN stations (Basic MultiPoint, up to 4 stations). The ISDN terminals should be High
Impedance.
- Select the High Impedance option for the Short MultiPoint arrangement and place the
440A4 terminating resistor adapter at both information outlets. Up to four ISDN terminals
can be connected after both 440A4 adapters. In this arrangement, the NT1 appears in
the middle of the transmission path and the two information outlets are at the ends.
Note: The circuitry of the 8500-Series terminals contains a set of terminating resistor
jumpers, labeled ON and OFF. ON enables the terminating resistor, and OFF
bypasses the terminating resistor. The installer can change the terminating resistor
options by changing these jumper settings.

A great teacher, does not provide answers, but methods to teach others "How and where to find the answers"

bsh

35 years Bell, AT&T, Lucent, Avaya
Tier 3 for 25 years and counting
 
Yes, I did read it, but I don't think you fully read what I wrote and skipped over it. Or, I did fully clarify my scenario.

Right now, I am experimenting with two and two only to see if it can do what I want it do on my own. Then, I will move on full-scale which would be for 113 additional phones using the 110RA1-12's since that would be easier. But, I am only working on two lines right now as I am the only one funding it. We have a time constraint and the process to buy anything through my company is very arduous. So, I need to verify that I can do this, on my own, and be fully functional, before I commit myself to the purchase order effort.

And, I do not want to buy a terminating block as of yet. Basically because I paid for the two terminating adapters myself to try it out in my office next to the punch down blocks. Then, I will try it in an adjacent building where they have a requirement for two more phones but we are limited in wire pairs. I have to provid demonstrated ability to double up phones with these devices to my superiors. Or else it will not happen.

Also, as I am using TN556's and they are a 4-wire, S/T interface. I do not have an NT1 in use, anywhere. The request about an NT1 in my original post was in reference to other equipment that I have seen and would require a 2-wire, U-Interface. If I am correct.

So, to reiterate...

I want to add an additional phone per port. I am using an Avaya G3 which has TN556C's which have a 4-wire interface to be precise. I have AT&t 8510's and Tone Commander 6210T's. I am experimenting myself with my own time and my own money with the 440A4 and a homemade splitter using modular jacks with a matching wiring diagram to the BR851B. I am only doing this for two ports, no more, no less. If I can add an extension to existing two ports and with the two aforementioned devices, add two extra phone at two desks, I am a happy-camper.

For purchasing reference I posted those two links in my previous post so I can use that for pricing when I go through the PO process here. It'd be easier for me to buy the splitter than punch down 113 homemade ones and to buy everything from one place and not two.

If it helps I am using this Avaya support document to guide my efforts in the wiring, last page, as it pretty much will match my test setup:


Basically, what I am getting from this is that I can go:

TN556 -> 440A4 -> splitter -> two phones

Which, as soon as the parts come in I will do. Which may or may not come in next week. I should have chosen 2-day.
 
terminating resitor only connects in-line with one of the
phones on the same port.

tn556 -> splitter -> 440A4 -> 8510#1
-> 8510#2

A great teacher, does not provide answers, but methods to teach others "How and where to find the answers"

bsh

35 years Bell, AT&T, Lucent, Avaya
Tier 3 for 25 years and counting
 
see attached

A great teacher, does not provide answers, but methods to teach others "How and where to find the answers"

bsh

35 years Bell, AT&T, Lucent, Avaya
Tier 3 for 25 years and counting
 
It works! Yay!

Any ways, one last question: Is Avaya the only company that manufactures a terminating resistor block? I only ask in reference to pricing as it is $103.01 with ground shipping. I am fine with that but its always good to have a few quotes.

eb
 
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