Elk M1 ==> Comcast VoIP ?


Active Member
Comcast is advertising that their digital voice service works well with most monitored alarm systems (http://www.comcast.com/images/ImageLibrary/FAQ/PDF/home%20alarm%20system%20reference%20sheet.pdf), but I can't tell what they are doing differently from other VoIP providers who caution that their service does not always work with monitored systems. Has anyone tried monitoring their M1 over Comcast's digital voice service? What monitoring service are you using? How do you have the RJ31X wired?

Sorry, don't have Comcast's phone service, but I do use VoIP on Comcast Broadband. My VoIP provider is VoicePulse, and my monitoring company is NextAlarm. I had some issues using NextAlarm's "preferred" protocol, Contact ID. I had to switch to SIA signalling to get reliable reporting.

I don't know specifically what would make Comcast's VoIP different from other providers. I do know they use a separate "band" for VoIP... it is not part of your internet bandwidth, and supposedly doesn't run the risk of getting choked off by excessive internet usage. So for one thing, you wouldn't need to worry about using any kind of QoS - that's already built in to Comcast's network. There may also be some latency advantage, since Comcast's POP will be local to you. For me, I believe VoicePulse's network is homed in NJ, so calls I make have to travel via the internet to NJ, then go from there. I know when, for example, I call my cell phone from my home phone to test different QoS settings, with one phone in each ear, there is a VERY noticeable delay between me saying something, and hearing it out the other phone. I don't know how much of that is due to the VoIP network, and how much is due to the cell network, but it's enough to make you wonder.