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Community Member

%Insufficient HDLC resource for pri-group


I'm adding a VWIC-1MFT-T1 to a cisco 1751v router with 12.3 IOS for use with a PRI. The router already has two DSP's so at least it should handle 12 channels/calls.

However, when enter the command:

pri-group timeslots 1-24 (or any combo)

I get this error:

Router(config-controller)#pri-group timeslots 1-12,24

%Controller tdm clock does not have data capability

%Insufficient HDLC resource for pri-group - it has been removed

I've seen the bug that this error was reported in and says just reload the router. Well, that doesn't do it. The VWIC is in Slot2 as there is a WIC-T1 in Slot1. I've even tried Slot0 just because, got the same thing.

Anyone ever seen this before?

Hall of Fame Super Red

Re: %Insufficient HDLC resource for pri-group

Hi Scott,

I remember reading some posts on this issue once before. The missing command was (I think the "both" is key);

tdm clock T1 2/0 both export line

From this excellent doc;

Hope this helps!


Community Member

Re: %Insufficient HDLC resource for pri-group

I just plugged that in there rather than the "voice" I tried "both". But this VWIC is in Slot2, which of course is Voice only...

Router(config)#tdm clock t1 2/0 both export line

% T1 data switch not available for this configuration

Hall of Fame Super Gold

Re: %Insufficient HDLC resource for pri-group

Can you upgrade to like, latest 12.4 and try again ?

Community Member

Re: %Insufficient HDLC resource for pri-group


If I move the VWIC to Slot1 and the WIC-T1 to Slot0 it works.. I wonder what that'll do to my WIC-T1 though. Probably just need to move the commands over to the different interface..

Community Member

Re: %Insufficient HDLC resource for pri-group

Did you Issue the command :

network-clock-participate wic 1

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