VoIP woe's - Why alarm systems need a POTS line
I saw a flurry of discussion on /. a week or two back about some Canadian (and American) home security companies having issues with clients who use a commercial VoIP solution, like Vonage. Apparently the systems are problematic or incompatible.
Well, no duh. VoIP is not the same as POTS when it comes to telephony service. Archaic as it may seem, some of us get quite nostalgic over the memory of a big, heavy, clunky off-skin-tone-beige phone with the large wire running from the case (no RJ-11 jacks you youngsters...the cable ran up inside the casing like some sort of techno-primordial vestigial tail). And when the electron dance of currents and frequencies was just in that particular state of perfection, the magic of zinc plated bells struck by steel hammers rang out with a brash **RINGGGGGG**. Ah, the good old days.
If you grew up any time before, say, 1987 or so, you should remember what I'm talking about. Phones that had no power cord and did not require 110volt outlets or any other modern contrivances. They simply hung on the wall, or sat on the table, and the cable ran into the box on the base boards, and it rang when it needed to, and you picked it up and got that familiar dull buzz of our now digitally recreated but less pleasing dial tone. If the power went out, you could pick up the phone, get a tone, and dial the utilities company, or the police, or your local pizzeria, depending on your priorities and needs.
Nowadays you have to ask at the electronics store where the "corded" phones are, and suffer the humiliation of scorn from a "sales person" who still uses pimple cream religiously and can't wait to get his drivers permit. But I digress.
The major point in this reminiscing is that POTS lines provide power to the end device. They are the original PoE solution (well, maybe not the original...the telegraph probably holds that distinction). So long as your phone had a connection to the main line out of your house, and that line connected to the trunk box in your neighborhood, odds were good that you could make a call, if the bill was paid. VoIP requires so many other systems to be connected, properly configured, and all working together nicely before you can check if Blockbuster has a copy of The Ringer. I know, the intricacies of Ma-Bell and the generations of infrastructures evolved from her since she was disbanded are no meager feats of engineering, but way back when, your TelCo took care of all of that for you.
With VoIP, you must have at the minimum:
- Working electrical current
- Internet service/presence
- specialized hardware device to connect phone to, or PC with proper audio/video input and output capabilities and software
- service provider for said specialized device, which can be substituted for open network solutions like Asterisk, but this requires higher technical skill on the end users part to setup
(by the way, none of these are normally managed by the same provider)
Alternatively, any of the following may contribute to the success, or failure, of your phone service availability
- firewalls, routers, network shaping devices
- network traffic load
- marathon World of Warcraft raid sessions
- whims of the internet routing daemons (not Unix daemons, but the actual spirits behind the magic routing routines of TCP)
Ok so obviously I've been quite lighthearted and humorous about this subject, at least in my own opinion, but the point is serious. If your phone service depends on the quality, stability, and availability of your Internet service, then phone service can never, ever take priority over and above the internet service. It simply can't. You can make an arbitrary decision in your head that it does, but if the internet service is degraded or not working, there is no way on earth your phone service will not be affected.
Now that may be acceptable for a lot of people under a lot of circumstances; it is for my family with our second and third phone lines out of the house (I'm dreading my kid's teenage years). But let me be the bogeyman and put a worst case scenario before you. When someone is in a medical emergency, a real crisis that requires immediate skilled responsiveness to prevent their death or permanent disability and suffering, in that situation do you consider your Internet service more important than your phone service? Probably not.
I am not on the payroll of Qwest or Verizon or Cingular or AT&T or Lucent or anyone else. Yes, many (all?) of them are probably VeriSign clients in some way, but I do not interact with them professionally, and I'm not denouncing or endorsing anyone or either type of service. But if you put your home security alarm on your off-the-shelf VoIP phone line, and the burglars cut the power to your house so they can break in easier, you shouldn't be surprised when the alarm system can't call the police because your VoIP line is dead, since the computers, PBX, router, cable modem, and network equipment just went down with the power to the house. Yeah, that's a bit of a movie terror plot, but the point is valid if the scenario is farfetched.
I'm a big fan of my commercial VoIP phone line for my home office. I've taken the box with me on trips when I knew I had to make a lot of calls and didn't want to run up a hotel long distance bill or cellular phone bill. But I always have at least one POTS line in the house. We use VoIP for long distance calls to the grandparents out of state and what not, but there's always 1 phone that doesn't need to be plugged into the 110volt to work. And until internet access is ubiquitous and available to the level that POTS service is, this won't change either.
Professionally, we call that business continuity planning. At home I call it common sense.
