Digital Telephone

[thymer]

A home phone is way too important to trust to VoIP. VoIP was the "rage" several years ago in the telcom industry until everyone figured out that the technology was expensive and it, well, stinks. It requires a very robust network and lots of equipment. From a cable modem type perspective it's not anywhere near as reliable as a POTS line (Plain Old Telephone Service) and tends to not work when the power goes out. Even if you have a generator for your house a lot of the cable company equipment isn't on UPS so you don't have dial-tone. VoIP is out there and maybe one day it will be something but for now there's nothing more reliable than a POTS line.

 

[justleesa]

I have a phone with and answering machine etc.....When the elec. is out, so is our phone. Newer phones also need electricity, don't they?

 

[MikeC]

I have a phone with and answering machine etc.....When the elec. is out, so is our phone. Newer phones also need electricity, don't they?

No, unless it is a cordless phone. I have never unplugged the answering machine to see if the phone in the kitchen still functions. I have a plain old phone in the bedroom that works as long as Verizon works.

 

[shark.byte.usa]

I have my digital telephone through Cox bundled with digital cable and high speed internet. Works great, not a single problem, can't even tell the difference, I've had it for years. Only thing is you can't dial 10-10-220 or any of those funky long distance carrier access codes, and you can't have a differnt long distance carrier, what the cable co. charges is what it is. Mine runs through my telephone jack like normal, maybe it's VoiP, I never really thought about it or cared.

 

[MikeC]

We are talking about two different systems. You properly describe the sort of backups the Sonet/SDH/telecom world has. However, a hybrid fiber coax system, typically used by cable companies to provide cable and internet service is a quite different type of system. A star network of fiber replaces the old rigid coax main trunk. This improves TV channel quality and often lets the cable system expand to more channels. The optical star network fans out across the city and is converted back to electrical signals on the cable in neighborhood nodes that typically serve between 200 and 1000 customers. It's these fiber to cable nodes that are the weak link in the system. Often they are NOT backup powered. That's why you can lose cable service due to a blackout several blocks away.

BTW, if you have slow upstream cable modem performance during peak usage periods, the most likely cause is that there are too many users on your neighborhood node. All users share the same 5-42MHz upstream or reverse channel.

Charlie, you sound like a CATV engineer. When I left Adelphia in '97 they were about 50% done building a "network" like you describe to serve the suburban Buffalo area. I do not know if they used battery backups or not. I know the old copper trunk did have backups.

BTW folks, how much traffic can the cellular system take in an emergency? Also check the quality of signal you have. There are several areas in my county where cellular service is not great, not because I live in the sticks, but rather people have fought having towers built. They think they hurt property values. That info came from service providers themselves.

 

[Charlie99]

Charlie, you sound like a CATV engineer..

Even more fun ... before retiring in '98 I used to run the applications engineering group and strategic planning groups of a linear & analog oriented semiconductor company. Everything from strategic planning to writing the detailed specs for new products to helping customer engineers design their systems. So one day I'd be talking with the Scientific Atlanta, General Instruments, CableLabs guys over on the cable side; then the next day I'd be working with engineers from hardcore telecom companies like Tellabs, ADC, Alcatel, Nortel, etc. The cable service providers generally had a different idea than the telecom guys as to what "high reliability service" meant.

Every year, the cable companies get better on things like reliability and backup power, but it's a change in mindset from the original cable TV systems where a few hours of outage per year wasn't a big deal. Meanwhile over in the telecom world, the nearly unbreakable, super reliable Plain Old Telephone Service set the reliablity mindset and standards for the rest of the telecom system as it evolved.

An always-on dialtone is a pretty safe assumption with DSL or telecom company provided gear, but with a cable company it's a good idea to explicitly check.

Charlie Allen

 

[justleesa]

No, unless it is a cordless phone. I have never unplugged the answering machine to see if the phone in the kitchen still functions. I have a plain old phone in the bedroom that works as long as Verizon works.

OK cool...I know that I gave one to my parents that has a digital phone book and it also has a plug - not cordless...and it doesn't work either if there is a power outage. I am sure that there are just models out there that do and don't work.

 

[CBulla]

I have had absolutely no issues with my VoIP at all. It's been incredibly reliant. The only down times have been brief periods when they had planned upgrades.. oh and durning Hurricane Charley.. but everyone was hosed then. POTS was on, where it wasn't damaged by flooding. We had that all back on in a few days when power was restored, till then we used CB and cell phone charged in the car to call around.

The difference is I pay $20 a month for what Sprint wants to charge $63 - do the math.

 

[MikeC]

OK cool...I know that I gave one to my parents that has a digital phone book and it also has a plug - not cordless...and it doesn't work either if there is a power outage. I am sure that there are just models out there that do and don't work.

Lisa, the phone next to me only has a phone cable on it, no bells or whistles. It works as long as Verizon, the phone company, does. Every home should have a phone like this if you have regular telephone service. It does not matter brand or color, push button or rotary. The electronic phones, like you have mentioned, need power plus phone service to work. If you only have those types of phones at home go to Best Buy or Target and spend $15 on a regular phone. Test it and then stick it in the closet if you wish to continue using the more advanced phones. When power dies, open the closet and use the $15 phone.

 

[justleesa]

Lisa, the phone next to me only has a phone cable on it, no bells or whistles. It works as long as Verizon, the phone company, does. Every home should have a phone like this if you have regular telephone service. It does not matter brand or color, push button or rotary. The electronic phones, like you have mentioned, need power plus phone service to work. If you only have those types of phones at home go to Best Buy or Target and spend $15 on a regular phone. Test it and then stick it in the closet if you wish to continue using the more advanced phones. When power dies, open the closet and use the $15 phone.

Yeah...that's what I thought