TELECOM@Usc-Eclb (05/28/82)
TELECOM AM Digest Friday, 28 May 1982 Volume 2 : Issue 68
Today's Topics: CCSA Networks
What If... - Phone Pholklore
More On Xerox's Internal Network
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Date: 27 May 1982 10:56-EDT
From: Jeffrey Krauss <KRAUSS at MIT-MC>
Subject: CCSA Networks
Both FTS and Xerox's Intelnet are examples of the Common Control
Switching Arrangement (CCSA) networks offered by AT&T. A CCSA network
is a network of leased lines that link a customer's premises by means
of switching machines at telco central offices (instead of using
customer premises PBXs). The leased private lines used in CCSA
networks are provided by AT&T and OCCs for the exclusive use of the
customer, and are not shared among CCSA customers. The telco central
office switches, however, are shared among CCSA customers (and
possibly with the public switched network also). CCSA service was
first offered by AT&T in 1964, at the request of General Electric. As
of 1974, AT&T had 29 CCSA customers. The FTS is the largest CCSA
network. A CCSA network is configured much like the public switched
network with a heierarchy of switching machines; higher level
switching machines provide a tandem function for interconnecting
intermachine trunks and provide alternate routing capabilities. The
lower level switches connect access lines to one another (for intra-
regional connections) and connect access lines to trunks (for inter-
regional connections). One major difference between CCSA networks and
tandem tie line networks that use PBXs is that CCSA networks have a
"uniform numbering plan"--every station has a unique seven-digit
address. In contrast, a tie line network that involves tandeming
through PBXs requires an access code for each inter-PBX trunk that is
needed to complete the connection (the user must define the routing
and set up the trunk connections at the time he dials.)
The Autovon network is totally different. The switching machines are
multiply interconnected in a non heierarchical network, probably much
like the Arpanet, for survivability. The telephone sets have an
additional four buttons that can be used to seize trunks for
high-priority calls in an emergency--lower priority calls can be
disconnected without warning if a higher priority call needs the
trunk. The netowrk is 4-wire end-to-end, whereas CCSA access lines
are typically two-wire.
---Jeff Krauss---
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Date: 27 May 1982 10:47:45-CDT
From: jon at uwisc
Subject: what if...
The following appeared in the Milwaukee Journal, May 26.
Thought you phone pholks might enjoy it:
... we got to wondering how the course of American economic
history might have been changed if Alexander Graham Bell had had
a different name -- say, Alexander Graham Klunk.
Would we now have the Klunk System instead of the Bell
System? Furthermore, what sound the the inventor have used as a
means of alerting people that a call was coming through?
For Alexander Graham Bell, of course, the answer was easy --
the phone should ring, like a bell. But Alexander Graham Klunk
might well have thought differently. His telephone might have
gone "Klu-u-unk, klu-u-unk, klu-u-unk," and everybody nowadays
would rush to answer the klunking telephone.
Or it could have been worse: What if his name had been
Alexander Graham Siren? Life would be intolerable.
Bell's first utterance on the telephone was the famous line,
"Mr. Watson, come here. I want you," spoken to an assistant in
another room.
What if this answer had come from the other end?
"This is Mr. Watson. I've stepped out for a minute. After
the tone, please leave your name and number, and I'll get in
touch with you as soon as I return. Thank you. (Buzzzzz)"
Eerie, huh? Maybe Bell would have thought the whole thing
over and said, "Forget it -- the telephone will just get people
mad. I'll invent something else, like the hula hoop." ...
[the text reprinted here was originally enclosed within disussions with
Don Ameche, who played Bell in the 1939 film "Alexander Graham Bell"]
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Date: 27 May 1982 09:37 PDT
From: Suk at PARC-MAXC
Subject: Re: Internal phone networks
To: Hamilton.ES at PARC-MAXC
"This results in some interesting anomalies. I'm in El
Segundo, and I can't direct-dial someone across town in
Pasadena, but a Xerox person in Rochester can!"
On the other hand, using the same system we can direct-dial (from Palo
Alto) Stockton (~60 miles) or Fresno (~100 miles), but not Sacramento,
Lake Tahoe, Chico, Eureka, etc. (all farther away).
Stan
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End of TELECOM Digest
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