AT&T’s recent national outage of their U-Verse voice service affected me for most of one day last month. Until recently, such outages never affected me because I was still using a traditional landline phone service. That all changed a few months ago when I decided that the risk and consequences of an outage might be offset by the additional services and lower cost of the VoIP service over the landline service. Since the outage, I have been thinking about whether I properly evaluated the risks, costs, and benefits, and whether I should keep or change my services.
The impact of the outage was significant, but not as bad as it could have been. The outage did not affect my ability to receive short phone calls or send and receive emails. It did however severely reduce my ability to make outgoing phone calls and to maintain a long phone call as the calls that did get through would randomly drop. I had one scheduled phone meeting that I had to reschedule as a result of the outage. Overall, the severity and duration of the outage was not sufficient to cause me to drop the VoIP service in favor of the landline service. However, if more similar outages were to occur, say more frequently than on a twelve months cycle or for more than a few hours at a time, I might seriously reconsider this position.
An offsetting factor in this experience was my cell phone. My cell phone sort-of acts as my backup phone in emergencies, but it is insufficient for heavy duty activity in my office because I work at the edge of a wireless dead coverage spot in the mountains. I find it ironic that the cell phone has replaced my landline as my last line of defense to communicate in emergencies because I kept the landline so long as a last line of defense against the wireless phone service going down.
Many people are making this type of trade-off (knowingly or not). A May 12, 2010 report from the Centers for Disease Control and Prevention, says that 24.5% of American homes, in the last half of 2009, had only wireless phones. According to the repost, 48.6% of adults aged 25 to 29 years old lived in households with only wireless phones. The term VoIP never shows up in the report, so I cannot determine whether or not the data lumps landline and VoIP services into the same category.
Going with a wireless only household incurs additional exposures of single point of failure. 9-1-1 operators cannot automatically find you in an emergency. And in a crisis, such as severe storms,
the wireless phone infrastructure may overload and prevent you from receiving a cell signal.
The thing about single points of failure is that they are not always obvious until you are already experiencing the failure. Do you permit single point failures in the way you design your projects or in your personal life choices? For the purpose of this question, ignoring the possibility of a single point failure is an implied acceptance of the risk and benefit trade-off.
If you would like to suggest questions to explore, please contact me at Embedded Insights.
[Editor's Note: This was originally posted on the Embedded Master]
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Redundancy over all-in-one
I would never rely on one vendor or media for my voice, data, video, etc. I have Cable and DSL giving me redundant data, voice is available over copper, VOIP, and wireless, and broadcase video is available over IP, cable, and HD antenna (never used so far). We are far too dependent on our services to allow a single point-of-failure, and piggybacking services just makes the failure worse!
It’s worse than you think…
We lived though a couple of hurricanes in Florida. We had both landline and cell phone services. During one hurricane the first to go was the landline (a bunch of trees took out phone and electrical lines). The landline phone line came back in a couple of days (though as an aside, everyone around us had a wireless phone. Without electricity these do not work. As it so happens I collect antique phones from the 1930′s. To this day these still work).
Though we still had plenty of “bars” on the cell phone we could not get a line. At first we thought it was a cell tower (or two) down (I know, there would have been little or no “bars”). After a day or so everyone around us seemed to get their cell phones back. We did not. Once things got back to normal (a couple of weeks without electricity, though we had a big generator) I started looking into why we didn’t have cell service. Though I could not get it “officially” confirmed (and I tried) I was told by one service rep that a “major military service” contracts with the cell carrier and “during times of emergency” they take precedence over “consumers” and a great part of the available bandwidth is given to them. When I repeatedly tried to get confirmation of this I was treated as if I was un-American for even questioning if this might be the case or not.
Since then we’ve moved to Kansas (traded hurricanes for tornados) and changed cell carriers. We have Cox Communications (with the “total” package internet, cable TV and phone) here and I’ve opted for VoIP with them for our “land-line”. One thing I found out is this; if you have both a modem for internet and VoIP these are given priority over internet only for just the reason you state (9-1-1). Prior to getting the VoIP modem I had drop-outs with the internet. Once we got the “combo” modem I have yet to lose either internet or phone line. Of course, living through it a couple of times I know that in time of emergency the best things you can have is a good “old-fashioned” CB radio, a generator and good supply of gas.
When all else fails
As you can tell from my handle I am an amature radio operator (ham). One good reason to get your license is for situations such as these. The ham community has a long tradition of helping out in emergency situations. They have the equipment, the skills and the experience. The licensing has never been easier (no more code) and there are many resources available for studying. If you are reading this, you probably can pass the tests on the first try. Get licensed!
73 de KC6ZUT
Wrongly stated question….
It’s not “Do you permit single points of failure”, the real question is “how many single points of failure do you live with daily”. Car dies, you walk. Whole house AC quits, you sweat. Drunk driver hits pole, you retire early. But I don’t keep a 2nd car in my trunk, nor a bag of ice in my freezer, nor a portable generator in my backyard. Cost/benefit ratio given rarity of events does not warrant these backup measures.
9-1-1
I keep a land line for calling 911. It doesn’t happen often, but sometimes. and when it does you need it bad. Cell phone for 911 has about a 50% failure rate here in San Jose, either busy, or keeps ringing. Plus landline voice quality is better than cell phone. And once I have the landline, paying extra for voip is not worth it in my situation. Finally, cable modem (comcast) does go down occasionally, but landline has gone done only once in the last 15 years for me. I also have a cheapy line-powered phone for power outages.
backups
The simple thing many forget is many people can’t afford a backup system, so they don’t have one.
Most people have a few backups for some things such as candles and matches, in case the power fails, and a flashlight or two, but as Americans the power system and the access to stores, etc. is so easy most don’t keep anything other than a few can goods around that could be used if the power was out for a few days or longer.
Modern life would be seriously hindered if something was to take out power stations over large areas, sure the military could come in and help and hospitals and police stations have backup power, but other essential places don’t.
Places such as grocery stores, hardware/department stores, etc. don’t have backups. I was in a grocery store a few years back and their telephone line went out, so no credit cards and no cash registers, as the cash registers also had to interface with the store chains server to register prices, so you couldn’t even get stuff with cash. They were only out for a short time but still it shows how dependant we are on our primary phones and electrical power grid.
California is due for a huge earthquake, there is no question in any scientists mind as there is a geologic record going back millions of years, and a big one is way the hell overdue, but I’ll bet most people who live in California don’t have shelf stable food, water, candles lanterns, etc.
As to backup on electronic products, even large corporation’s are in trouble if the power is down for a long while, servers, etc. usually have backup power, but otherwise most equipment has no backup at all.
And as to internal redundancy, people simply won’t pay for it unless they have to.