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

[CNTSYSNETAG]

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

[lgijssel]

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.

Regards,

Leo

[CNTSYSNETAG]

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

[spremkumar]

hi

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.

regds

[lgijssel]

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...

Regards,

Leo

[CNTSYSNETAG]

Hi there,

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

[lgijssel]

It should work from telnet after using the command:

term mon

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.

Regards,

Leo

[CNTSYSNETAG]

I tried that, but I only get no messages regarding the BRI-Interface:

gw01#term mon

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.

[lgijssel]

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.

Reagrds,

Leo

[CNTSYSNETAG]

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.

[lgijssel]

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.

[CNTSYSNETAG]

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?

[lgijssel]

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)

Regards,

Leo

[lgijssel]

Two links that might be useful in this respect:

http://www.cisco.com/en/US/partner/products/hw/routers/ps221/products_installation_guide_chapter09186a00801a0555.html#wp1005053

http://www.cisco.com/en/US/partner/products/sw/iosswrel/ps5013/products_feature_guide09186a0080080de8.html#xtocid118128

[spremkumar]

hi

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.

regds