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New Member

Cisco 2811 VoIP configuration

Hi Guys,

I have a Cisco 2811 router w/ IOS version 12.4(9)T1 SPSERVICESK9, configured with a VWIC-1MFT-E1.

I'm drop-in replacing an existing Cisco 2600 router with the 2811. The site runs Cisco IP Phones w/ SRST configured using an E1 PRI connection.

Because I want to do a straight drop-in replacement, I've pretty much copied the existing voice configuration verbatim. However, when I get to the "voice-port" command, the router complains - there's no "voice-port" command available to me.

Looking at the original router, it has an NM-2V network module installed (which is hardware incompatible with the 2811 *doh*). I haven't bought an equivalent NM-HD-2V for this router yet, and am suspecting the following:

* The NM-HD-2V network module provides the "voice-port" command ability; or

* I have the wrong IOS image installed on the 2811 router.

Also, can someone please tell me the difference between an NM-HD-2V, and an NM-HDV2, apart from the fact that the HD-2V network module provides 2 x VWIC slots, and the HDV2 module doesn't?

I look forward to your replies.



Rebecca Richards

Hall of Fame Super Gold

Re: Cisco 2811 VoIP configuration

Hi Rebecca,

Please check that you have codecs in the 2811, in the form of PVDM installed in the router. Show diag will tell you this. The VWIC will use these newer codecs.

Then, please check you correctly configured that the controller E1, pri-group, and isdn-incoming voice.

As far as I know, both the NM-2V and NM-HD-2V are compatible with the 2811.

You IOS image is fine.

New Member

Re: Cisco 2811 VoIP configuration

I thought that I'd configured the E1 "pri-group" and "isdn incoming-voice voice" on the router, but hadn't *doh*.

Once I'd entered the appropriate IOS incantations, the mysterious "voice-port" appeared within the configuration.

Life is now sweet :)

I don't need the NM-HD-2V or NM-HDV2 modules, and thus can stick to my original design - using the NME-16ES-1G-P module for the phones.

- bec

Hall of Fame Super Red

Re: Cisco 2811 VoIP configuration

Hi Rebecca,

We just started using the 2811's recently so I can't answer all of your questions. But here are a few that may help;

The Cisco 2811, 2821, 2851, 3825, and 3845 voice routers do not support the NM-1V and NM-2V voice/fax network modules.

From this doc;


2-slot IP communications voice/fax network module.

Supports up to eight channels of analog/BRI voice using medium complexity codec or six channels using any supported codec. (No support for T1/E1 or data WAN)

From this doc;

NM-HDV2 (You will need this version)**

IP Communications High-Density Digital Voice/fax Network Module

Supports a VIC/VWIC slot that can fitted with either digital or analog/BRI voice/WAN interface cards. Supports a maximum of 60 channels of digital voice, or four channels of analog voice in medium complexity codec. Must be used with up to four PVDM2 Packet Fax/Voice DSP modules.

From this doc;

Hope this helps!


Hall of Fame Super Silver

Re: Cisco 2811 VoIP configuration

You can also use the onboard HWIC slots to insert the VIC cards if you have not filled them up with other cards. On 2811 you have 4 available HWIC slots for that purpose, if you have some available then you won't need any NM cards.



New Member

Re: Cisco 2811 VoIP configuration


Thanks for that!

Based on your response, I can now see that the primary difference is the NM-HD-2V cannot handle E1, which is what we have in some of these offices.

Which now begs the question, why use these cards at all in the 2811, which I've configured with PVDM2's? Additional port capacity?

- bec

New Member

Re: Cisco 2811 VoIP configuration

hmmm... I think I've discovered why I would want an NM-HD-2V - I can't get "voice-port" when using an WIC-1B-S/T.

Is this theory correct?

New Member

Re: Cisco 2811 VoIP configuration

*sigh* to round out this discussion, no it's not. I need a VIC2-2BRI-NT/TE.

I've just had a look at one of the remote office's production router where the office has an BRI drop-off, and it has an "TE BRI Voice daughter card" sitting inside an NM-2V

- bec

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