Without the number of the calling party, the Cisco router does not know which 'Dialer profile' to associate with the incoming call, and rejects the call.
I kept a record of the log from the Cisco router, before and after enabling CLID, so here we can see the differences.
While doing the testing & troubleshooting, I had debugging enable on the cisco router as follows:
#show debug
Dial on demand:
Dial on demand events debugging is on
The following ISDN debugs are enabled on all DSLs:
debug isdn error is ON.
debug isdn event is ON.
debug isdn q931 is ON.
First an incoming data call, before BT enabled CLID on the ISDN line:
ISDN BR0 Q931: RX <- SETUP pd = 8 callref = 0x01
Sending Complete
Bearer Capability i = 0x8890
Standard = CCITT
Transfer Capability = Unrestricted Digital
Transfer Mode = Circuit
Transfer Rate = 64 kbit/s
Channel ID i = 0x89
Called Party Number i = 0x81, '67xxxx'
Plan:ISDN, Type:Unknown
ISDN BR0 EVENT: process_rxstate: ces/callid 1/0x14 calltype 1 HOST_INCOMING_CALL
ISDN BR0:1: Incoming call rejected, unbindable
ISDN BR0 **ERROR**: host_incoming_call: DIALER ERROR 0x1: b channel 0, call id 0x14
ISDN BR0 EVENT: process_rxstate: ces/callid 1/0x14 calltype 1 HOST_DISCONNECT_ACK
ISDN BR0 Q931: TX -> RELEASE_COMP pd = 8 callref = 0x81
Cause i = 0x8095 - Call rejected
After BT enabled CLID, which was done within a couple of hours, the log shows this:
ISDN BR0 Q931: RX <- SETUP pd = 8 callref = 0x01
Sending Complete
Bearer Capability i = 0x8890
Standard = CCITT
Transfer Capability = Unrestricted Digital
Transfer Mode = Circuit
Transfer Rate = 64 kbit/s
Channel ID i = 0x89
Calling Party Number i = 0x2183, '142761xxxx'
Plan:ISDN, Type:National
Called Party Number i = 0x81, '67xxxx'
Plan:ISDN, Type:Unknown
ISDN BR0 EVENT: process_rxstate: ces/callid 1/0x17 calltype 1 HOST_INCOMING_CALL
BR0:1 DDR: Caller id 142761xxxx matched to profile
%DIALER-6-BIND: Interface BR0:1 bound to profile Di1
I also tried making a voice call to the ISDN number, which I knew would fail, just to see what it looked like. Here is before CLID was enabled:
ISDN BR0 Q931: RX <- SETUP pd = 8 callref = 0x01
Sending Complete
Bearer Capability i = 0x8090A3
Standard = CCITT
Transfer Capability = Speech
Transfer Mode = Circuit
Transfer Rate = 64 kbit/s
Channel ID i = 0x89
Called Party Number i = 0x81, '67xxxx'
Plan:ISDN, Type:Unknown
ISDN BR0 EVENT: process_rxstate: ces/callid 1/0x11 calltype 2 HOST_INCOMING_CALL
ISDN BR0 **ERROR**: host_incoming_call: Received a call with a bad bearer cap from <unknown> on B1
And here is a voice call, after CLID enabled:
ISDN BR0 Q931: RX <- SETUP pd = 8 callref = 0x01
Sending Complete
Bearer Capability i = 0x8090A3
Standard = CCITT
Transfer Capability = Speech
Transfer Mode = Circuit
Transfer Rate = 64 kbit/s
Channel ID i = 0x89
Calling Party Number i = 0x2183, '142768xxxx'
Plan:ISDN, Type:National
Called Party Number i = 0x81, '67xxxx'
Plan:ISDN, Type:Unknown
ISDN BR0 EVENT: process_rxstate: ces/callid 1/0x19 calltype 2 HOST_INCOMING_CALL
ISDN BR0 **ERROR**: host_incoming_call: Received a call with a bad bearer cap from 142768xxxx on B1
By the way, the Cisco router was a 1721 using IOS v12.3
#show version
Cisco Internetwork Operating System Software
IOS (tm) C1700 Software (C1700-Y-M), Version 12.3(26), RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2008 by cisco Systems, Inc.
Compiled Mon 17-Mar-08 14:24 by dchih
ROM: System Bootstrap, Version 12.2(7r)XM1, RELEASE SOFTWARE (fc1)
System returned to ROM by power-on
System restarted at 12:53:16 GMT Wed May 21 2008
System image file is "flash:c1700-y-mz.123-26.bin"
cisco 1721 (MPC860P) processor (revision 0x100) with 28231K/4537K bytes of memory.
MPC860P processor: part number 5, mask 2
Bridging software.
X.25 software, Version 3.0.0.
Basic Rate ISDN software, Version 1.1.
1 FastEthernet/IEEE 802.3 interface(s)
1 Serial(sync/async) network interface(s)
1 ISDN Basic Rate interface(s)
32K bytes of non-volatile configuration memory.
16384K bytes of processor board System flash (Read/Write)