Unanswered Question
Apr 27th, 2007

I am newbie in Voice over IP.

I have cisco 2821 chassis (12.4 ios) in each office, and 2 PBX with PRI card. I nead to connect PBX in offices via IP network (use PRI card of PBX in each office). I nead medium quality.

I read many manuals, i think i nead this modules in each office router:

1. VWIC2-2MFT-T1/E1

2. PVDM2-64

1 E1 port in stock.

It is enough? Or which modules i nead buy to cisco 2821?

Have someon working example configuration?


P.S. Sorry for bad English.

I have this problem too.
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Paolo Bevilacqua Sat, 04/28/2007 - 02:06


you can do this even with 2801 if you want. Please contact your Cisco reseller and ask for the voice bundle. The bundle routers comes with a PVDM2 already and you may add more depending on you needs.

Do you want to do compressed or uncompressed voice, and do you want to provision the full E1 capacity, or how many calls do you want to support ?

Based on this we can tell you the exact hardware requirements.

andrey.iliyov Sat, 04/28/2007 - 02:42


I already have had a cisco 2821 routers, and I think we can use it.

At first time we nead the full E1 (30 calls support).

We nead compressed voice in a medium quality.

1. VWIC2-2MFT-T1/E1

2. PVDM2-64

It is enough?


At next time we plan to use a 3 E1 ( 90 calls support). But for this task we plan to buy more modules (3 module PVDM2-64 and VWIC2-2MFT-T1/E1 + VWIC2-1MFT-T1/E1 modeles in all).

2 another E1 we plan to use in a next task (not for an offices PBX communication).

Paolo Bevilacqua Sat, 04/28/2007 - 03:23

Hi Andrey,

Yes the PVMD2-64 is the minimum to support 30 simultaneous calls of g.729a compressed voice. The quality will be good, not just medium.

You can also use VWIC-2MFT-E1. That is a previous model that works fine and can be found for a lower price.

The 2821 will allow you to add two more PVDM2-64 so you can expand to the three E1 that you need in the future.

Hope this helps, please rate all useful posts using the scrollbox below!

Paolo Bevilacqua Sat, 04/28/2007 - 12:15

Thanks for the nice rating, Contact me privately for more advice, my email is in my profile.


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