Reza, you are most welcome, the history and development of telephone switching
is very interesting and at risk of boaring everyone to tears I will
now relate the true story of the automatic exchange/PBX.
A long, long time ago there was funeral director called Stroger.
Stroger lived a very quite life somewhere in the mid-west. When someone in the
town died the first
thing a relative would do is call the operator and ask for "The funeral parlor".
Mr. Stroger's phone would then ring and the operator would say "Hi Mr Stroger
Emee-loooo's
old man just up and died.... Here I'll connect her thru" and so on, and so on.
One day, Stroger realised that the other funeral director in town was taking
most of his business and
the phone didn't ring nearly as often.
It didn't take long in a small town to know why. The new telephone operator
happend to be the wife of his competitor!
So Stroger sat down and used his swedish engineering heritage to figure out a
way of selecting who you wanted to call
without using an operator.(direct dialing)
What he came up with was a selector relay which could select one of ten
contacts arranged in a circle
depending on the number of on/off pulses on the telephone line.
By stacking these one on top of another the rotor could select (by going up and
down
and turning around) a hundred or so connections. (2 Digits)
So the rotary phone and the Stroger switch was born and the operator was
replaced by the branch exchange.
Oh yes...and they lived happily ever after.
Henry
Reza - Asterisk Enthusiast wrote:
Gentlemen!
Henry, Jim, Frank, Thank you!!! Combination of those responses was
truly enlightning! Frank, yes, you are one of us... You inherit the
Torontonian status for being one of us and having your son in this part
of the border :). Andrew, thanks a 2^10 terra bytes for going above
and beyond with the explanation.
The explanations were wonderful, well written to the point anyone could
understand. Yes, this was the extreme low level answer that I was
seeking - and as usual, with answered questions, raises MORE questions ;).
So I guess, technically this "timing device" could have been reworded as
a "synchronization device", where the voice packets are properly
synchronized in a MeetMe/MoH function where dancing in rythm with the
correct beat and correct number of step is in harmony with the rest of
the dancers?
But the primary difference here is the dancers are clients transmitting
voice packets, and the number of steps is 1000 per second (boy, would
that be a hard salsa move per second).
So does the cheap clone X100p/x101p I have in 3 of my * boxes, provide
ENOUGH synchronizing capability for lets say - practically speaking 30
clients in MeetMe, and theoritically speaking 100 clients in MeetMe?
I have two boxes at two data centres with access to 10mpbs backbone...
and giving a lot of thought in teleconferencing services area, where
each prospect/client has the potential to have about 6 - 10 people
calling from different geographic locations in Canada & the US.
Just another information about my boxes... none of them are connected
physically to a PSTN line. ALL DIDS & voice packets arrive from
several VOIP carriers/servers. No transcoding happens on my boxes. No
call recording. No other services. Just pure VOIP. My co-located
boxes are single CPU, P4 2.0 with 1 gig ram.
I owe all you gentlemen a beer! Jim, I guess you are banking on beer
eh? Now you have 2 beers on me! Frank... you must come to Toronto
more often... Canadian beer is better :). Americans flocking to Canada
on the weekends is proof enough!
Cheers & thanks again to everyone!
Best,
Reza.
