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

12.0(7)T routers can't start VoIP session

Hi there,

One of our customer is using VoIP, on their WAN. There was an AS5300 at the head office to terminate the ISDN PRI, and there are FXS ports on the branch offices. On friday a PS problem occurred on AS5300, and we changed it with an Cisco 3640 with IOS release 12.2(17) with the interface cards NM-HDV+VWIC-MFT-E1. Now the branch offices with 12.0(7)T release can not start VoIP session with this router, but the 3640 can initiate and make VoIP session successfully. On the same WAN I have another 3640+NM-HDV+VWIC-MFT-E1 hardware that these branch offices can start VoIP with this router. Only difference between these two 3640 routers configuration is connection of PRI to PSTN -framing/no framing- setting.

Does anybody have any idea about this situation?

Thanks in advance,


Cisco Employee

Re: 12.0(7)T routers can't start VoIP session

I know that 12.0(7)T is positively ancient.

upgrade to the same IOS on all gateways and see what happens.

New Member

Re: 12.0(7)T routers can't start VoIP session

Hi Crieman,

I know the IOS is really old, but it's imposibble to upgrade the IOS on these days. My customer doesn't have enough memory and flash on their routers for this operation.

Hall of Fame Super Gold

Re: 12.0(7)T routers can't start VoIP session


look on the leading auction side for cisco flash ram and flash. I used a reputable seller and was always happy.