Digital Voice. Is it the same as VoIP ?

USA (SANEPR.com) July 2, 2009 -- Digital phone service, or Digital Voice is essentially the same as VoIP (Voice over Internet Protocol), however, the network that the voice travels over is private - as opposed to "The Internet" used by VoIP which is public. So, your VoIP service from a company like Vonage goes out onto the public internet and has to deal with everything that entails. Your Digital Voice Service from a company like Comcast travels over its own private network, or at least as far as the Comcast telco equipment. If you are calling another person who has a VoIP line, then you are only 50% better off, as part of the call will go over the public Internet. I Hope that clears things up for a few people - it did for me.

Now, let's clear up the statement that "VoIP and Alarms don't mix".

Just like the the "Digital Phone Service is VoIP" statement is partially true, let me clarify why people think that alarm systems do not work using VoIP adapters. Firstly, a VoIP service provider has control over some of the network settings (namely the audio codec) between your VoIP adapter and the number you are calling. All they care about is providing crystal clear human voice for their customers. They do not care about your alarm system and it just so happens that many of the technologies used in providing clear human voice have a deteremental affect on alarm signal transmission.

Something outside of everyones control is network jitter or latency. In simple terms - delays from one end to the other. VoIP service providers try their best to work around it. Once again, the technologies and methods they employ are at the expense of reliable alarm transmission. At this stage you must be thinking that alarms do not work with VoIP and although it is possible to get some good signals thru - the statement rings true.

So, let's take the VoIP service provider out of the equation and what you are left with is a "raw" Internet connection. Place a VoIP adapter in your home or business and an IP receiver at the Monitoring Center and what you have in effect is your own private network - a "controlled" path to the Monitoring Center. Even though the data still travels over the public internet, you have full control over the optimsation technologies and you can adjust them to suit how an alarm panel works - not a human voice.

There are actually at least two or three technically different ways to make alarm systems work over IP. The most reliable method uses raw IP packets as opposed to making an audio call. Armed with an off the shelf Linksys VoIP adapter that is specially provisioned for alarm monitoring as opposed to human voice, it is 99.9% reliable to send alarms over the internet. The availability of the internet connection obviously cannot be gauranteed, however, at least with the advantage of line supervision over IP you will get to know about loss of network or line cut within a few minutes. The Linksys SPA3102 has an FXO port that can be used for fallback to POTS or cellular dialer if you do not have full confidence in your internet up-time.

So there you have it. That's what all the fuss is about.