How many PRI's can a 3725 handel

Unanswered Question


I have a 3725 router with 1 pri dedicated to voice. I am in the process of getting 2 more pri's for a total of 3 pri's. My question is can my route support them. I know that the router suppots 2 AIM slots which will be used by 2 AIM-VOICE-30's but if I have 3 PRI's that is a total of 69 channels and I only have enough DSP's for 60 Channels. So do I need a new router or will this configuration work.

Thank you

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
paolo bevilacqua Thu, 06/21/2007 - 07:27
User Badges:
  • Super Gold, 25000 points or more
  • Hall of Fame,

    Founding Member


yes you are correct, 69 channels won't fit in the 3725 via AIM-VOICE-30. But, if you want to hang on to this router for a little longer, and you have a free NM slot, you could try an NM-HD-xxx (too many variants to list here) that wold support the the additional T1s without need for the AIM, as it has DSP on-board. See what modules are supported on your router:

Hope this helps, please rate post if it does!

rseiler Fri, 06/22/2007 - 21:13
User Badges:
  • Silver, 250 points or more

Don't use the AIM-VOICE-30 module, use the NM-HDV2-* modules which have the same PVDM2 DSP modules as the ISRs.

I have several c3725 routers running with 2 each of the NM-HDV2-2T/E1 modules (total of 4 T1 ISDN PRI trunks) with 50-60% CPU under full call volume.

I had a bunch of issues with the AIM-VOICE-30 modules as they are a single (older) 5510 DSP and have significant software limitations.


This Discussion