ISDN dial-in with Cisco 1721 and WIC-1B-S/T

Question

Hi there,
we use a Cisco 1721 with a WIC-1B-S/T interface for ISDN backup purposes. I configured the Cisco 1721 and connected the BRI-WIC to a ISDN channel. When I try to test the ISDN connection, I always get the error that the line protocol is down. The WIC is connected to the ISDN correctly. I do not understand why the line protocol is always down. Could anybody help? The chosen encapsulation is PPP, the ISDN Switch Type is basic-1tr6 (I think thats the right one for Germany). The IOS version is 12.4 (1c).
Regards, J. Schroeder

Answer 1

Hi there,
the BRI interface is connected to a telephone system and not directly to a NTBA. The hostname matches the username, is this right? When I try to dial out, I get this messages:
*Mar 9 16:28:11.804: ISDN BR0 **ERROR**: host_disconnect_ack: Unfound B-channel on Disconnect_Ack call id 0x8003
*Mar 9 16:28:33.792: ISDN BR0 **ERROR**: CCBRI_Go: NO CCB Src->HOST call id 0x8003, event 0x5 ces 1
*Mar 9 16:29:47.324: ISDN BR0 **ERROR**: host_disconnect_ack: Unfound B-channel on Disconnect_Ack call id 0x8004
*Mar 9 16:30:09.312: ISDN BR0 **ERROR**: CCBRI_Go: NO CCB Src->HOST call id 0x8004, event 0x5 ces 1
*Mar 9 16:30:12.952: ISDN BR0 **ERROR**: host_disconnect_ack: Unfound B-channel on Disconnect_Ack call id 0x8005
*Mar 9 16:30:34.940: ISDN BR0 **ERROR**: CCBRI_Go: NO CCB Src->HOST call id 0x8005, event 0x5 ces 1