ISDN2 BRI Trunk

[crossmark76]

Hi Guys,

I am trying to configure an ISDN2 BRI trunk but for all my will and might of trying I cannot get the 2 lines up!!!

What i need to confirm is the pin outs so I know I have stamped on the correct RJ45 pairs!

So what i have is an ISDN2 line coming in which is converted to a CAT5, from here I have stamped pins 4&5 (blue & blue/white) to pair one on our chrome frame and pins 3&6 (green & green/white) to pair two but the trunk does not come up!

I have tried a loopback and this does not bring the trunk up either but I am not sure if this would work being a digital card (TN2198).

Does anyone out their know if this loopback should work or not???

Thanks
Mark

 

[mattKnight]

This looks to me like you have a S/T presentation and a U card.

S/T are 4 wire presentation, from a NTE and U are 2 wire direct from the carrier.

Do you know which you have?

Take Care

Matt
I have always wished that my computer would be as easy to use as my telephone.
My wish has come true. I no longer know how to use my telephone.

 

[crossmark76]

This is where I get confused.

The line coming into the building goes into a ISDN BT box, out of the back of that there are 2 RJ45 ports - I assumed (maybe wrongly) that if I had one cable plugged I would get a 128k circuit so if both RJ45's were used I would get 2 64k circuits which would be compatible with the TN2198 card....

Is that what you are asking?

Thanks
Mark

 

[mattKnight]

>Is that what you are asking?

Yes.

BT (and most UK providers) present ISDN2 as S/T (4 wire).

I *think* the TN2198 is a U (2 wire) card and won't work, but my experience with circuit packs is limited...

In essence, the TN2198 combines an ISDN trunk card with a NTE in the same package. BT have provided (as they always do) an NTE.

The line coming into the building goes into a ISDN BT box, out of the back of that there are 2 RJ45 ports

The 2 ports are to allow multiple bits of equipment to sharethe line. Each piece of equipment cna have a TEI, which identifies it uniquely to the line.

I assumed (maybe wrongly) that if I had one cable plugged I would get a 128k circuit so if both RJ45's were used I would get 2 64k circuits which would be compatible with the TN2198 card....

Sadly, A bad assumption. The 4 wire connections are split as send and receive rather than 64K on 1 pair and 64K on the other.

AS I say, U presentation is unusual in the UK (I've never personally seen one.) Where did you get the TN2198 from? Do you have a support partner who can help?


Take Care

Matt
I have always wished that my computer would be as easy to use as my telephone.
My wish has come true. I no longer know how to use my telephone.

 

[crossmark76]

Thanks Matt you help is much appreciated.

So I have the wrong card then as there looks to be no way I can botch the wiring to become cmpatible, do you know what card I need to find that is compatible with the S/T presentation...

Mark

 

[crossmark76]

One more stupid question :/

I have found this pinout
RJ45 Plug for ISDN S/T bus
==========================
1 N/C
2 N/C
3 White/Green ..... Receive +
4 Blue ............ Transmit+
5 White/Blue ...... Transmit-
6 Green ........... Receive -
7 White/Brown ..... -48VDC (option)
8 Brown ........... -48VDC Return (option)


Can I not use pins 3 and 6 for one channel and 4 & 5 for the other?

Mark

 

[crossmark76]

This looks to be the card I am looking for...

Avaya Definity TN2185B ISDN-BRI 4-Wire S/T-TE Interface Card