[Boatanchors] WAS Goodies NOW Bell

[Richard Knoppow]

On 4/12/2015 6:22 PM, GRANT YOUNGMAN wrote:
> In the very old days, it was true that telco COs had copper to every endpoint, and had massive wet cell battery banks to keep things running as long as the CO wasn’t put out of commission by something.
>
> However, the system hasn’t looked like that in a very long time — except maybe in some rural areas with very small Central Offices.  SLCs or (Slics) are neighborhood or area subscriber line concentrators that feed user endpoints with copper, but which are connected back to the CO via T-1 or greater spans, some copper, a lot more fiber these days.  The voice channel is digitized there, too —  depending on the Slic’s technology into either TDM channels or VoIP channels.  In any case, you haven’t gotten CO battery power at your kitchen landline for a long time.  It comes from limited (8 hours if you’re lucky, more likely maybe 2 hours) battery associated with the Slics.  When that’s gone, your phone line goes dead.  If the Slic is damaged your phone goes dead even if the CO is up and dry and humming along.
>
> We live in a world of limited battery power, and limited failsafe — whether it’s wireless, wireline, or tachyon beams :)
>
> Grant NQ5T
>
>
     This is one of the reasons telcos wanted to convert to fiber; they 
wanted to get out of the power supply business.  Old style phones had to 
have dialing current and enough power to work the carbon microphones as 
well as ringing current.  Modern electret microphones and touch tone 
oscillators still need power but its far less than the old type phone. 
Some phones get ringing current locally.  I am not sure what kind of 
system my POTS phone is on, it could well be connecting to a local 
concentrator.

-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL