Cisco 2821 w/ 4-port ISDN NM-4B-U in China, no B-Channel found

[kuhna]

Hi, i?ve got a Cisco 2821 with 4-port ISDN NM-4B-U card (Integrated NT-1) directly connected to ISDN in China. For some reason i can?t place a call, always receive error "ISDN BR1/0 **ERROR**: host_disconnect_ack: Unfound B-channel on Disconnect". Once customer places own Cisco router (unknown model/IOS) with NM-4B-S/T card to an external NT-1 ate same ISDN lines he can establish calls without any problems. My Router has an IOS 12.4(9)T1. Is there any special config requested to get this working? Thnx for all feedback in advance, Andreas.

[bwilmoth]

This issue is due to the hardware problem caused in the BRI card. Replacing the card with the new one will solve this issue.

[kuhna]

Hi bwilmoth, , thnx for reply, but do you mean simply replacing the old NM-4B-U card with a new one or with a NM-4B-S/T? Regards Andreas