CME-ISDN-T1_E&M_wink_start<=>ISDN-T1_E&M_wink_start-NortelPBX<=>PSTN

I am deploying a Cisco CME in my company and I want to tie it to the Nortel Norstar MICS phone system at the same site. We created a T1 tieline. We can make extension to extension calls without a problem. When we try to make calls to the PSTN from the CME we have some channels on the T1 that is not able to make calls. My PBX guy say the problem is with the Cisco configure. My Cisco TAC rep say he is passing all digits and there's nothing wrong on his side and he suggest that the Nortel tech replace the PRI connected to the CME.

I am using 16 channels. I can make calls to the PSTN from these channels on my T1 tieline: 1,3,4,6,7,10,13,15,16.

I cannot make calls out of channel 2,5,8,9,11,12,14.

I wanted to implement qsig, but my Nortel guy tell me that his system doesn't support it. So I have to implement E&M. He does have NI2 and a couple of other PRI switch type signaling.

I also notice that when we call PBX to PBX all channels works, but on the channel that we cannot get from the CME to the PSTN when I hangup the call on the Nortel the CME doesn't teardown/hang up the call, but on those bad channels if I hangup the call on the CME's phone the call is teardown correctly on the Nortel's phone.

This is an old key system, but we ask the Nortel PBX guy to buy an ISDN/T1 card for the system which we thought was new. Now we finding out this card is an old card that was in production for years and work without any noticeable problem. So I think that some of the ports may not be sending the disconnect signal correctly. Now it could be the Cisco is not recognizing the disconnect signal or is getting a disconnect signal when it try to connect to a trunk connected to the PSTN (trunk to trunk transfer).

We are seeing in the CME debug when the Cisco CME try to make a PSTN bound call on the bad channels it recieve a disconnect signal from the Nortel right away, but the Cisco phone that made the outbound call remain active and get a busy tone then we get another dial tone. When we get the second dial tone we can call any extension on the Nortel. That is why I think it maybe something with the Nortel, but it's up in the air.

Can someone please help me?