Author Topic: Contentious and rambling Analog multiplexing for connecting PABX to Central Office discussion  (Read 3938 times)

Alex G. Bell

  • Guest
Land lines are extremely non-versatile in reality.  What other purposes might they be used for other than for analog telephone calls ?
The one strength that they do have is that they work without local power.  AFAIK all VoIP solutions require the end user to provide power.  If commercial power fails, in an emergency it may be impossible to call for help.  Of course in a widespread emergency help may not be available anyway but in a local one it might well be.

The Vz letter about copper retirement says nothing about the customer needing to provide an AC outlet but does advise the customer to keep a spare "D" cell available to maintain operation during commercial power outages exceeding 24 hours. 

Their failure to advise customers of the need to provide an AC outlet is going to result in many Vz installers going out to migrate the service being unable to complete the task: a recipe of their own incompetent choosing for a huge waste of their manpower.

unbeldi

  • Guest
The one strength that they do have is that they work without local power.  AFAIK all VoIP solutions require the end user to provide power.
Certainly.  But they become useless too with the vast majority of telephone sets sold today that operate with a wall wart (and have no batteries), and go dead just the same as an IP phone or ATA.  Many cable Internet access providers supply cable modems or VoIP adapter with a battery backup. I got one in recent years that provided for 6 or 8 hours of backup power.

bellsystem

  • Guest
Well, all of the telephones I own now, and will ever own, will not require any power besides that supplied over the telephone line.

Say what you will, but it must be admitted that the older systems are better and more reliable for power outages and emergencies.

unbeldi

  • Guest
Certainly.  But they become useless too with the vast majority of telephone sets sold today that operate with a wall wart (and have no batteries), and go dead just the same as an IP phone or ATA.  Many cable Internet access providers supply cable modems or VoIP adapter with a battery backup. I got one in recent years that provided for 6 or 8 hours of backup power.

The optical network termination equipment installed in multi-dwelling structures, such as by VZ in apartment building in cities, usually have local batteries installed to keep them operating for some time.

I think the subscription rate to fixed line services has dropped to below 40% of all subscribers in the US, so even with a land line in case of emergency, you can only call four out of ten destination anymore with your working land line.  And most of those are probably old folks that most young people don't want to call anyways.


Alex G. Bell

  • Guest
Certainly.  But they become useless too with the vast majority of telephone sets sold today that operate with a wall wart (and have no batteries), and go dead just the same as an IP phone or ATA.  Many cable Internet access providers supply cable modems or VoIP adapter with a battery backup. I got one in recent years that provided for 6 or 8 hours of backup power.
6-8 hours is almost nothing.  Even routine weather events in cold areas can produce outages much longer than that.  This is without considering rare events on the scale of Hurricane Sandy.  I know people who were without power for weeks as a result of that.  Living without heat, hot water or use of a stove you could still need to call for a medic or police.

unbeldi

  • Guest
6-8 hours is almost nothing.  Even routine weather events in cold areas can produce outages much longer than that.  This is without considering rare events on the scale of Hurricane Sandy.  I know people who were without power for weeks as a result of that.  Living without heat, hot water or use of a stove you could still need to call for a medic or police.

Well, it is somewhat of a hypothetical benefit.  Makes you feel good, or at least better. The people you most likely will call have dead iPhones by then.

The meaningful activity would be to advocate for reliable power systems.  Does it not seem inconceivable that mankind can send humans to Moon, and have robots operate on Mars for years and years, while being incapable of maintaining stable power in our cities ?   Where is a sense of  priority in that ?

Alex G. Bell

  • Guest
The optical network termination equipment installed in multi-dwelling structures, such as by VZ in apartment building in cities, usually have local batteries installed to keep them operating for some time.
Apparently not.  The copper retirement notice I saw was sent to someone in a 64 unit 13 story urban building.  If the ONT is going to be in the basement the customer would not need to provide access to a Vz installer nor keep a spare "D" cell handy.

unbeldi

  • Guest
Apparently not.  The copper retirement notice I saw was sent to someone in a 64 unit 13 story urban building.  If the ONT is going to be in the basement the customer would not need to provide access to a Vz installer nor keep a spare "D" cell handy.

Correct, the ONT units in the basement are not individual units for each apartment, but serve multiple customers each.  They should have some backup too.  I think, but I am not sure, some can also be powered via the fiber optic cable.   There are even optical power feeds where the termination device is powered by a high-power optical feed that is converted to electricity at the terminating end.

Alex G. Bell

  • Guest
Well, it is somewhat of a hypothetical benefit.  Makes you feel good, or at least better. The people you most likely will call have dead iPhones by then.
I don't see people being able to call 911 for a medic or police action as hypothetical.

The meaningful activity would be to advocate for reliable power systems.  Does it not seem inconceivable that mankind can send humans to Moon, and have robots operate on Mars for years and years, while being incapable of maintaining stable power in our cities ?   Where is a sense of  priority in that ?
Theoretically possible but as with so many human endeavors, politics and conflicting interests get in the way.  Humans on the moon and robots on Mars?  Guys like Elon Musk are talking about establishing a human colony on Mars. 

Apparently the reliability of the power grid is far more precarious than in the past.  According to reliable sources the power grid is now very vulnerable to severe damage due to sabotage via the net than it was in 1966, 1978 and 2003 when large blackouts occurred just due to "ordinary causes".  It would take months to recover from such an outage due to lack of spare equipment and the disappearance of domestic manufacturers. 

With events such as the Wannacry worm and similar reports this very day reports about the vulnerability of the power grid hardly seem implausible.
« Last Edit: June 27, 2017, 04:35:03 PM by Alex G. Bell »

Alex G. Bell

  • Guest
Correct, the ONT units in the basement are not individual units for each apartment, but serve multiple customers each.  They should have some backup too.  I think, but I am not sure, some can also be powered via the fiber optic cable.   There are even optical power feeds where the termination device is powered by a high-power optical feed that is converted to electricity at the terminating end.
That's the approach that seems intuitively obvious, technically feasible and a minimum requirement to meet public safety standards required in the past but apparently is not what they are doing, judging by the contents of the letter they are sending out.  This is not hearsay or innuendo.

unbeldi

  • Guest
Apparently not.  The copper retirement notice I saw was sent to someone in a 64 unit 13 story urban building.  If the ONT is going to be in the basement the customer would not need to provide access to a Vz installer nor keep a spare "D" cell handy.

I think I misread your statement.

I guess one has to examine what is installed in each situation.   The replacement system is adapted to the existing wiring in the building.  It may require installing local VDSL links for each customer from the basement.

Alex G. Bell

  • Guest
I think I misread your statement.

I guess one has to examine what is installed in each situation.   The replacement system is adapted to the existing wiring in the building.  It may require installing local VDSL links for each customer from the basement.
There certainly is already a pair from the basement to each unit so there is absolutely no technical obstacle to putting a common ONT in the basement.

Perhaps they are taking this much more costly and labor intensive approach so they have an excuse to wire the building for FIOS.  Perhaps they have scammed some PUCs to allow themselves to write off part of the FIOS wiring costs as part of a program to upgrade the voice network to fiber.

Many multi-unit buildings also use entry phone systems which intercept each unit's landline pair in the basement to provide direct access for visitors to call up a resident.  A single ONT in the basement would maintain compatibility with that widely deployed type of system.  An ATA in each unit would require an additional pair from the unit to the basement to back feed the ATA analog port to the basement "enterphone" system and back up to the unit.

Victor Laszlo

  • Guest
Quote
Well, all of the telephones I own now, and will ever own, will not require any power besides that supplied over the telephone line.

I suspect that you will be a very lonely guy, in the future.  Have you ever heard the song "All alone, by the telephone." by Irving Berlin?
« Last Edit: July 06, 2017, 06:57:08 PM by TelePlay »

Victor Laszlo

  • Guest
Since you are relatively new here, can you tell us a little about your experience in telephony? You seem to have the whole system figured out, and certainly know what you want, in technical terms. Are you a student of engineering? What types of phones and phone equipment do you collect or play with? You mentioned a future PBX. What do you see as your first system?  A step switch, crossbar, electronic, etc?
« Last Edit: July 06, 2017, 08:13:44 PM by TelePlay »

bellsystem

  • Guest
SxS (Strowger) switches are my favorite but it would not be practical for a primary PBX... it would be impossible to hook it up to the PSTN directly anyways,

So an electronic one. Currently, I have the Panasonic 308 and 824 analog PBXs with 4 rotary and 3 pushbutton phones. And in the process of collecting them, I managed to convince StopSmartMeters.org to collect about 60 telephones!

A common battery system is better. While a PBX makes the topic of a common battery kind of a N/A scenario, for homes with a single landline connected directly to the PSTN, common batteries are more feasible. They don't have to worry about anything.

Think about the things in your home with NO common battery. TV cable box. Modem. Router. The telephone is the only appliance with a common battery. And that is why uptime is 99.999%. Monopoly and centralization are more effective and efficient in the landline business.