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
Even in Germany you are likely to run into Euro-isdn.
Try basic-net3 for a change!
Use "debug isdn q921" to verify your layer2 connection to the isdn network. You should see both Rx an Tx as a result.
Thank you. I changed it to basic-net3, but that doesn't solve the problem. I tried 'debug isdn q921', as the rsult I only get "debug isdn q921 is ON"!?
Regards, J. Schroeder
You may want to check show log for the results if you have already enabled logging or else keyin terminal monitor and start capturing the outputs.
better you can telnet the router via simple hyperterminal where you have the option to do a telnet too.
Like spremkumar, I would advise you to verify that you have logging to the console or telnet session on.
Toggle the LAN interface and check if you get any message on your screen as a result from that.
If that is verified you may retry the procedure as I posted before. This should generate some debug output. If not, you might have no proper physical connection to the ISDN network.
Did I hint you to enter "no shut" on the BRI interface? Pretty basic, so it might not be needed but one never knows...
thank you so far. I added the "no shut" to the BRI interface. The problem is that I only have access to the Cisco 1721 via Telnet and SDM, no console is available at this moment. The next thing is that I do not get any debug messages in the log regarding to the BRI interface.
Regards, J. Schroeder
It should work from telnet after using the command:
Going in and out of config-mode ("conf t" and then "end") should generate messages to your telnet session. If this is true, your logging is working.
You stated that the line is properly connected. On this kind of lines you will then have plugged the cable from the router into an NT1 device?
If it remains in a non-working condition you will have to go to the router and verify the physical connection.
I tried that, but I only get no messages regarding the BRI-Interface:
gw01# Feb 10 14:35:33.930: %SYS-5-CONFIG_I: Configured from console by admcntag on vty1 (xx.xx.xx.xx)
No more messages at all.
And that was with isdn q921 debugging on?
In that case your isdn connection is not working.
Most likely is a provider issue bu a faulty WIC is also a possiblity.
Yes, this was with q921 debugging on. Could it be a problem that the WIC is not connected directly to a NTBA? The WIC is patched to a telephone system.
This might not be the same as an ISDN connection.
Many PBX vendors implement their own protocols on the link between their phones and their PBX.
Yes, thats right, but we did many tests to verify that ISDN connections from others PCs throug ISDN cards to the PBX are possibile. Only ISDN connections using the WIC are not working. So we have to check if it wotks directly with a NTBA, haven't we?
If there are other nodes that are working with this exchange, you will be able to determine the required protocol (1TR6 or Euro) on one of those.
After that, connecting directly is a logical next step.
You may need to check the methid for tei negotaition and the mode of operation (point-point or point-multipoint)
Can you revert whether you are using a S/T interface or U-Interface ? with the later one in place you dont need external NT box but with the former one you need to have an external NT box.
I checked that the OK LED is not turned on. I think this LED should turn on after the BRI interface was configured, right? Does anybody know what I have to do when the OK Led is off all the time?
Thanks, J. Schroeder
why dont ake a loop cable and insert it on the bri port if u get the brio is up line protocol is up(looped) then the card is ok.
then proceed with the term mon
ISDN TEST CALL INTERFACE BRI0 dialer string
the try for encap ppp
ppp authentication chap
the see that the dialer made at the router to which ur connectig matches the hostname.
the hostname at the bri end should match the username.
try doing this and then revert back
r u using the NT box or terminal adapter
then i am sure that there is a hostname and username mismatch try this out that is at the dialer portion and the bri part
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