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asak
join:2007-08-22
Katy, TX

asak to sturmvogel6

Member

to sturmvogel6

Re: 3rd party voip on Comcast cable modem

said by sturmvogel6:

You may want to:

1. Assign the VoIP device a fixed IP, e.g. 192.168.1.30 or at least note from the DHCP logs what IP it has.

2. Put this IP in the DMZ of the router

3. Reboot the VoIP device

4. Check that the IP is still the same for the VoIP device
I am not sure why this would be necessary because it has been communicating through the router for over a year without any problems, the only change is the ISP.

I believe it must be a contraint in the modem that prevents it from functioning. But I dont know what it is or how to fix it.

CableTool
Poorly Representing MYSELF.
Premium Member
join:2004-11-12

CableTool

Premium Member

[BQUOTE=asakI am not sure why this would be necessary because it has been communicating through the router for over a year without any problems, the only change is the ISP.

I believe it must be a contraint in the modem that prevents it from functioning. But I dont know what it is or how to fix it.
[/BQUOTE

FWIW, something working for a year, two years or two days prior really doesnt mean much. People use VoIP with EMTAs, Ive never heard of a reported issue. The CHSI port on the EMTA does nothing different then a regular modem.

sturmvogel6
Obama '08
join:2008-02-07
Houston, TX

sturmvogel6 to asak

Member

to asak
said by asak:
said by sturmvogel6:

You may want to:

1. Assign the VoIP device a fixed IP, e.g. 192.168.1.30 or at least note from the DHCP logs what IP it has.

2. Put this IP in the DMZ of the router

3. Reboot the VoIP device

4. Check that the IP is still the same for the VoIP device
I am not sure why this would be necessary because it has been communicating through the router for over a year without any problems, the only change is the ISP.

I believe it must be a contraint in the modem that prevents it from functioning. But I dont know what it is or how to fix it.
I have seen issues with a Vonage and a different VoIP provider boxes on the same network. I believe the Vonage box would reserve some ports for itself and then the secondary VoIP box would be stuck with no dialtone. Maybe that is what is happening between the VoIP device and the Comcast VoIP service.