Voice and Data on a VWIC using PRI

Unanswered Question
Aug 24th, 2008

I keep getting "channel-group 0 is already defined "

here is the config

controller T1 0/3/0

framing esf

clock source internal

linecod B8zs

channel-group 0 timeslots 16-23

when I add

pri-group timeslots 1-15,24

I get "channel-group 0 is already defined"

What seems to be the problem??

I have this problem too.
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Marwan ALshawi Mon, 08/25/2008 - 02:56

this channel-group 0 timeslots 16-23 in channel group 0

u need to defie the other one which is

pri-group timeslots 1-15,24

in another channel gorup

for example channel group 1 or 2

good luck

if helpful Rate

abyewondimu Mon, 08/25/2008 - 04:05

Thanks for your help. However, I am not trying to create another Channel group. I already have that for Data all I need is add Pri-group for voice.

pcameron Mon, 08/25/2008 - 04:04

The VWIC cards only have a single HDLC controller on them, so they can operate purely as data via a channel group, or dedicate this HDLC controller to the ISDN D channel for common channel signaling operation.

With the VWIC's, you cannot run a channel group AND normal ISDN operation on the same physical interface.

abyewondimu Mon, 08/25/2008 - 04:12

how do I dedicate the HDLC controller to the ISDN channel? I have seen couple of examples where VWIC-MFT1 is used for

channel-group and PRI-group on the same interface?

abyewondimu Tue, 08/26/2008 - 02:04

I found the solution:

when you assign a channel-group number the number which would be the beginning channel number of your channel group


I want to split a T1 between pri (voice)1-15 and Data 9(16-23)

so the config has to be:

pri-group timeslots 1-15

channel-group 16 timeslots 16-23

if you use any number from 1-15 you get an error

The channel has already been assigned to cas, pri, or tdm group


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