I have VOIP service from PhonePower...
They give their users an MTA device to connect to their network, however their instructions are that the user must turn on DMZ-Hosting for this device, to allow their service to work.
The problem I see with that is the warning message associated with this setting in my router's firmware. The following warning is given:
[ WARNING! Using a computer in DMZ mode opens the computer to outside intrusion, thus creating a security risk. ]
Additionally, my VOIP service with PhonePower seems to work fine right now without turning DMZ-Hosting on to recognize the mac-address of the MTA PhonePower device. So my logical conclusion thus far is---why should I turn on DMZ-Hosting, if my VOIP service seems to work fine without it?
When I pressed PhonePower for an explanation, they acknowledged that my overall security would be lowered with the router and their device if DMZ-Hosting is turned on and said its up to me how I choose to configure it, however they still maintained that it really should be on for their service to work. I responded by saying, "So, could that mean that even though my VOIP works now with DMZ off, that it might stop working again?" The response from PhonePower was, "Yes." I then asked if the reason for this is because my VOIP uses a separate network, to which they said yes.
Given the implicit warning I encountered in my router's firmware configuration, it still makes me scratch my head that a feature like DMZ would be required, especially since it would lower my overall security, as PhonePower indeed confirmed for me.
If I run into further problems down the road yet I still want to keep my VOIP service active, I guess I would have no choice but to turn DMZ-Hosting back on as suggested by PhonePower, but if my service works right now without it, I feel like it just makes more sense to keep DMZ off.
Any technical and objective insight into this matter would be greatly appreciated...