1841 with PRI for ISDN, is it possible?

Unanswered Question
Jun 11th, 2008


I got an 1841 router and installed a VWIC2-1MFT-T1/E1 card for our incoming PRI. I got the card setup for a T1 but when I try to do the pri-group config I get the following error:

%Please configure network-clock-participate wic 0 first

%Insufficient resources to create pri-group - it has been removed

If I try to enter the network-clock-participate wic 0 command I get an error. The command doesn't seem to be avaiable.

Our goal was to use this router as our ISDN backup router.

Should this configuration work?



I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (2 ratings)
ecornwell Wed, 06/11/2008 - 11:47

As dumb as this sounds, I used the setup utlitiy and it worked. I don't know why it wouldn't let me enter the command.

ecornwell Wed, 06/11/2008 - 12:53

Nevermind, as soon as the router reloaded I got the same message back.

Overall, will a 1841 with a VWIC2-1MFT-T1/E1 card work with the following configuration:

controller t1 0/0/0

framing esf

linecode b8zs

pri-group timeslots 1-24

interface Serial0/0/0:23

no ip address

encapsulation ppp

dialer rotary-group 0

dialer-group 1

isdn switch-type primary-ni

isdn timer t321 0

Then allow incoming and outgoing ISDN dial on demand connections...


ecornwell Thu, 06/12/2008 - 04:33

Thank you for that information but is that card something that is data specific? We've used the VWIC for our Voice PRI.

I'm a little confused that there wasn't better documentation for this stuff. I checked and that other card is 2x the cost.

Paolo Bevilacqua Thu, 06/12/2008 - 04:39

Hi, the VWIC is mainly made for voice PRI and channelized (not PRI) configurations. It is possible to use it for data PRI but on the bigger routers, not the 1841.

Last time I've checked the HWIC-1CE1T1-PRi is priced less than the VWIC2.

Sushil Kumar Katre Thu, 06/12/2008 - 08:14

Hi Paolo,

If you go through the datasheet of 1841 router it states that it supports VWIC modules only for Data.

I am also aware that these modules when configured for ISDN PRI can terminate only voice calls and can not be used for data connectivity.

I would like to understand what signaling is used for data connectivity when used on 1841 router.

Its a bit confusing for me.

-> Sushil

Paolo Bevilacqua Thu, 06/12/2008 - 10:50

VWIC can work as:

- channelized data w/o signaling, aka Nx64.

- CCS - PRI uses Q.931 and can be voice, data, or 3.1 KHz Bearer (proper fax and modem).

- CAS - R1 for N.A. and R2 any variant.

On the 1841 only first mode is supported.


This Discussion