24th chanel of T1 not working

[rod1]

Hi! We just implemented our outbound project couple of days ago. Our PABX was connected to consierto dialer throught T1 configuration with robbed bit signalling. My problem is that the 24th cahnnel of all my t1s are not working. Is the problem on my trunk configuration or on the dialer itself. The dialer by the way is Concerto dialer. Thanks.

 

[Bobg1]

If they are PRI T1's the 24th channel is used for signaling

 

[mikeydidit]

The 24th channel is the D channel and the rest are B's. The D channel is for associated signaling.

Mike Jones
LSUHSC

 

[rod1]

Thanks Bob and Mikey! Does usually the 24th channel always assigned to any type of T1 configuration? My T1 is not configured as isdn pri but an ordinary T1 with robbed bit signalling. This don't need a d channel right?

 

[bivsipostar]

Did you assigned port in trunk group form for member 24? Is other end of t1 assigned channel 24?

 

[avaya2004]

..Its nore lokking like a dialre issue..Check with dialer person that its configured for robbed-bit signalling..In robbed-bit, you get all 24 channles as bearer channles to carry voice traffic...
You can also try setting the ohm setting(75-120)on your DS1 board...I have heard that there few DS1 board with wrong switch lablelling..So you may try changing it..

Viren

 

[ken07734]

check your csu if any, maybe the csu is set for data instead of RBS.?

 

[rod1]

Thanks for all your response! We already assigned port 24 to both dialer and into the PABX. Our support of our MUX equipment here told us that their MUX is configured to 120 ohm impedance but the card on our PABX is set to only 75 ohms. I think Viren has a point. I will send you an updates as long as we changed the DS1 card setting on our PABX. Thanks!

 

[rod1]

Hi! Changing the impedence from 75 to 120 works! Thanks to you guys!!!