I'm trying to compile a list of available VME RS232 multiplexors and would
appreciate hearing of peoples experiences including whether the mux performed
as the manufacturer stated, what kind of I/O throughput you have measured,
and whether you think the mux supported most of the desirable features.
I'd also like to hear from people who had a significant amount of trouble
porting a particular mux...
PC
------------------------------
Date: Sun, 31 Jan 88 10:58:21 PST
From: dmr@russell.stanford.edu (Daniel M. Rosenberg)
Subject: What network am I on?
Reply-To: dmr@russell.stanford.edu (Daniel M. Rosenberg)
What is the 800 number one calls to find out what long distance
network is being used?
(E.g., I dial 1-800-xxx-xxxx and get a recording like: "Welcome to AT&T.")
Thanks for any pointers,
--
## Daniel M. Rosenberg '91 CSLI/Stanford University 1-415-323-0389
## dmr@russell.stanford.edu or ihnp4!decwrl!labrea!russell!dmr
------------------------------
Date: Thu, 04 Feb 88 11:35:59 GMT
From: Brian J Haughey
Subject: Voice-mail boards for PC's.
Hi all :
I'm trying to get some information together on manufactuers of VOICE-MAIL
boards for PC's. (Essentially these are boards which, when you plug your PC
into a PBX, will allow you to leave a voice mesage for someone, storing it in
APCM format on a disk for later retrieval).
If you know of any companies working in this (or related) areas, please
send any details to me at the address below. Thanks !
Arpanet : HAUGHD88%IRLEARN.BITNET@CUNYVM.CUNY.EDU
Bitnet/Earn : HAUGHD88 at IRLEARN
------------------------------
Date: Wed, 10 Feb 88 21:22:04 EST
From: CAPEK%YKTVMZ.BITNET@CUNYVM.CUNY.EDU
One of my colleagues asks if there's either a commercial device or an easily
buildable circuit which acts as an amplifier for the phones in a house on
one line. The problem is that when Grandma calls, everyone wants to be
on the line. But the CO isn't able to power 3 phones off-hook simultaneously.
Seems like it would be a common need, but I've never heard of anything like
that. And, of course, there's no real spec that's honored by the local
operating company about how many phones can be driven simultaneously.
Peter Capek
IBM Research -- Yorktown Heights, NY
------------------------------
Date: Sat, 28 Nov 87 20:46:12 EST
From: enger@sccgate.scc.com (Robert M. Enger)
Subject: Re: TELECOM Digest V8 #23
Doug Mosher recently wrote concerning "no ringing on the line".
I do not know the specifics of the case in question, so many explanations
are possible!! Given the information provided, it sounds like the number
being dialed was part of a Direct Inwards Dialing (DID) number group, and that
there was some difficulty with the DID trunks, amps, or pbx DID trunk cards.
Briefly DID service provides a PBX with direct to the station dialing by
repeating the last X digits dialed by the caller into the pbx, over
one of the pbx's DID trunks, usually using ROTARY PULSE signaling
(which is why DID usually has a longer delay before ringing is heard).
(Touchtone signaling from the CO to the PBX is available in some areas,
and speeds things up dramatically! Check with your local telco).
After the addressing has been passed to the pbx, the co cuts the voice path
through to the DID trunk, and the audible tones heard by the caller
are actually generated by the PBX.
I have seen cases where a PBX talk path has failed, but the control signals
and the functioning of the supervisory signaling of the pbx's DID trunk
circuit still work. The result is that the co thinks the trunk is ok,
the pbx and co handshake the new call coming in, but the caller does not
get to hear any audible indications. I have also seen cases where the
trunk amplifier/equilizer units in the CO (MFTs, I think they're called??)
have gone bad: they still pass line status handshaking info, but not
voice frequency, the result again, no talk path (as long as the addressing
is passed to the pbx with rotary pulse. I assume things would fail
if TT signaling were used through a bad MFT).
Should the trunk status handshaking fail (pbx powered down, trunks disconnected, etc), the CO will declare the trunks in trouble, and they will be taken out of service at the CO. Under this circumstance, a caller will hear some form of
audible indication from the CO itself, probably one of the busy tones.
In this day of high technology, wouldn't it be nice if the CO gave out more
definitive information when it could not complete a DID call into a customer
PBX? How about a nice simple voice recording for starters. Then we could get
fancy and actually identify the trunk group by number! (A DID trunk group
number is unrelated to the telephone numbers it services for the PBX.)
Some suggestions:
All direct dial Circuits into the customer PBX are in use.
Please try again later. Trunk group <xxx>.
The direct dial circuits into the customer PBX are not working.