Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

3662, DSPs, Dead Air/Call Drops, and No Ring-out

(This is already a TAC case - just taking a while so trying to see if others have run into anything similar - maybe get some other feedback :-)

We have a PRI MFT interface in our 3662 that interface with our NEC PBX via a PRI Card - the DSPs never seem to want to go active on a fresh boot of the 3662 - we always have to pull the PRI module out hot and replug it back in to work. We have an open case with TAC about it but have not gotten it resolved yet (we have another PRI module that behaves just the same - the IOS is 12.0(6r)T

On Friday we began to have sporadic problems with PBX users calling IP users and receiving dead-air on the other end - minutes later it would work - sporadic...there are never more than 6 channels in use on the PRI according to perfmon - then users started getting cut off in the middle of calls today while the dead air problem continues...

Every once in a while - the PRI card on the NEC PBX goes 100% active and then drops down to normal useage (again with logs showing no such increase in actual calls).

I want to suspect the DSPs - though we've already replaced the DSP and NMHDV and PRI card once - with the same results...does this seem like jumping to conclusions - would there be any reason to suspect anything else?

Keep in mind - it all worked well for 4 months except for sporadic lack of ringout up until Friday...

- Ken


Re: 3662, DSPs, Dead Air/Call Drops, and No Ring-out


It could be the IOS version! What protocol are you using to connect to the NEC. I've had problems with early 12 trains on 2600's that were supposed to support qsig and did apart from the MWI message which caused them to go into a never ending loop of the last 4 seconds worth of proccessing.

It is probably worth updating the IOS to something in the 12.1 range at least (personally I like 12.5t stuff 'cos it fixed my problem).

I've now seen a number of problems with DSP's that look like faulty hardware and IOS upgrades fixed them.


CreatePlease to create content