telecom@ucbvax.ARPA (03/19/85)
From: Jon Solomon (the Moderator) <Telecom-Request@BBNCCA>
TELECOM Digest Mon, 18 Mar 85 17:25:55 EST Volume 4 : Issue 171
Today's Topics:
Publishing Alternate Long Distance Rates (V4 #170)
Microcom Networking Protocol
Amtrak tel. no. & 301-731
April-May Communications Forum seminars
nenew F-O T1 lines
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Date: Fri 15 Mar 85 17:23:03-EST
From: Ralph W. Hyre Jr. <RALPHW@MIT-XX.ARPA>
Subject: Publishing Alternate Long Distance Rates (V4 #170)
To: TELECOM@BBNCCA.ARPA
Well, SBS Skyline DOES publish their rates (and the struture is simple enough
that I can easily program my Apple to compute the cost of a call 'on the fly'.)
Travel Rates Regular Rates (per minute)
U.S. Canada Mass/Adjacent Coast-Coast Anywhere else
Daytime .58 .81 .27 .43 .37
Evening .38 .60 .15 .24 .20
Night/Weekend .28 .38 .11 .17 .15
- Ralph Hyre
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Date: Sun, 17 Mar 85 17:12:59 est
From: Ken Mandelberg <km%emory.csnet@csnet-relay.ARPA>
To: telecom@Berkeley
Subject: Microcom Networking Protocol
I have been looking at some glossy literature for Microcom
modems, including their 2400 baud entries. The modems use
MNP (Microcom Networking Protocol) to allow error free
data transmission.
Here are some questions:
1) Does anyone know what the MNP algorithm is. I am really
only interested in the asynch case?
2) Does it work well under varying situations (no data - just
line noise, intermittent single character i/o, long bursts of
data). I would be worried that in the single character case,
the packaging might really cut down responsiveness. Remember
the raw data rate is only 300/1200/2400 on these modems.
3) Whatever the algorithm, there just has to be some overhead
even when there is no noise (and more when there is). The glossy
doesn't mention it, but I wonder if it the modem expects to
do flow control with the host and computer, and if so what
kind (XON/XOFF?)?. It strikes me that this could play havoc with
applications which use raw mode. The glossy has no mention
of a buffer in the modem.
4) The glossy says that MNP is rapidly becoming any industry
standard. (This is a little funny. Microcom has an advertisement
which shows a huge pile of their competitors modems, none of
which use MNP). Does anyone know what other modems use MNP, and
if there are other industry standards?
Ken Mandelberg
Emory University
Dept of Math and CS
Atlanta, Ga 30322
{akgua,sb1,gatech,decvax}!emory!km USENET
km@emory CSNET
km.emory@csnet-relay ARPANET
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Date: Mon, 18 Mar 85 10:59:51 EST
From: Carl Moore (VLD/VMB) <cmoore@Brl-Vld.ARPA>
To: telecom@Brl-Vld.ARPA
Subject: Amtrak tel. no. & 301-731
A telephone # at Amtrak, 400 N. Capitol St. NW, Washington,
DC 20001 is given as 202-383-3860, ATS 733-3860. I have never
seen ATS before.
301-731 used to be at Hagerstown, Md., but the tel. #'s on that
exchange were changed to 301-790 plus last 4 digits of old number.
Now 731 appears at Lanham ("Hyattsville" on phone bill; reachable
via 202 areacode); 790 in DC area is at McLean, Va.
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Date: Mon, 18 Mar 85 11:27 EST
From: Kahin@MIT-MULTICS.ARPA
Subject: April-May Communications Forum seminars
To: Kahin@MIT-MULTICS.ARPA
Massachusetts Institute of Technology
Communications Forum
Wideband Metropolitan Networks:
CATV and Alternative Possibilities
April 4, 1985
Stephen Weinstein, Bell Communications Research
New business and residential communications services +
will require wideband metropolitan networks with capabilities ,
beyond those of present telephone and cable television +
facilities. This seminar will describe the technical and +
political problems of building these capabilities into existing ,
CATV systems and discuss present and proposed techniques +
including hybrid systems using the telephone network. It will,
review the advantages of a distributed star network architecture -
and high bit rate optical fiber and discuss how these *
technologies are being introduced by telphone companies, CATV, ,
and other communications providers. Possibilities for advanced ,
services on a future network of this kind will also be +
considered.
Resource Sharing in Local Area Networks
April 10 (Wednesday), 1985
Leonard Kleinrock, UCLA
Distributed systems present a number of fascinating +
challenges, not the least of which is the problem of allocating ,
system resources to an unpredictable demand stream. This problem -
was presented to us in the form of wide area computer networks in -
the l970's and faces us in the form of local area networks (LANs) -
at present. The key issues and principles of resource sharing in -
LANs will be discussed including, for example, topology, access ,
method, and medium. The seminar will also review how these ,
problems have been resolved in current products and consider some -
likely new solutions.
Telecommunications Developments in Europe
April l8, l985
Peter Cowhey, University of California at San Diego
Eli Noam, Columbia University
The divestiture of ATfT and regulatory policies favoring ,
competition in long-distance telephone service have had a +
profound effect outside the United States -- especially in other -
highly developed countries: Japan, Canada, and the larger nations -
of Western Europe.
In Europe, the traditional PTT (Post, Telephone, and +
Telegraph Administrations) monopolies have been questioned. ,
British Telecom has an officially sanctioned competitor, and BT ,
itself has been privatized. While other countries have not ,
officially moved as much toward the American model, private ,
companies have entered new areas on the fringe of traditional ,
core services. Although impetus for policy change often derives -
from general arguments for deregulation and competition, much is -
also made of the need to stimulate European industry in order to -
export to the burgeoning American market.
Encoding Voice Signals
April 25, l985
Bernard Gold, MIT Lincoln Laboratory
Robert McAulay, MIT Lincoln Laboratory
Robert Price, M/A-Com Linkabit, Inc.
Although not visible to the public, vocoders (VOice CODERS) -
have been around for a long time. To date, however, technical ,
difficulties and cost have limited their use to such applications -
as secure communications for the military. This seminar will ,
discuss the historical development of vocoders, why they have ,
been used in the past, and the potential they have for enhancing -
public communications systems.
Long Distance Land Lines
May 2, l985
Gus Grant, Fibertrak
additional speaker to be announced
(note: to be held in Building 34, Room 401A)
With deregulation of long distance communications in the ,
United States, several corporations have announced ambitious ,
plans to build long distance land lines. Collectively, these ,
plans portend a dramatic increase in long distance capacity. ,
This seminar will discuss the market forces driving this +
expansion and the business strategies of some of the major +
competitors.
New Directions in Media History
May 9, l985
Douglas Gomery, University of Maryland
Morris Dickstein, Queens College
David Thorburn, MIT
New approaches to the academic study of film and other forms -
of mass media have gained prominence in recent years, as the ,
methods of traditional disciplines such as history, literature, ,
cultural anthropology, and economics have begun to be applied to -
contemporary audiovisual texts. Centrally interdisciplinary, ,
this emerging media scholarship promises new perspectives on the -
cultural significance of media texts and institutions and +
powerfully revises conventional accounts of their historical ,
development.
Marlar Lounge
MIT Building 37, Room 252
70 Vassar Street, Cambridge
Thursday, 4:00 to 6:00 p.m.
(except as noted)
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Date: Mon, 18-Mar-85 07:12:18 PST
From: Richard Shuford <vortex!richard@rand-unix>
Subject: nenew F-O T1 lines
To: Telecom-request@bbncca.ARPA
One more datum for those collecting T1 lore: During a recent
conversation with a New England Telephone network-maintenance
supervisor, I was told that all new T1 links being installed in
his territory (Vermont) were fiber-optic, not twisted pair.
He was not sure, but he believed that the F-O connections were
multimode graded-index type.
......RSS
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End of TELECOM Digest
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