eli@spdcc.COM (Steve Elias) (12/08/89)
somewhen, Xerox PARC did some experiments called "Etherphone".
has anyone heard of this?
or.. could anyone point me to a documents person/index at Xerox
where i might be able to locate information on Etherphone?
thanks...
--
-- Steve Elias ; eli@spdcc.com ; 6179325598 ; 5086717556 ; { *disclaimer(); }
lixia@ARISIA.XEROX.COM (Lixia Zhang) (12/09/89)
Yes PARC did an Etherphone project a few years ago (headed by Dan Swinehart, swinehart.pa@xerox.com). The Etherphones are still in use today at PARC. There is a tech report (CSL-89-2), "Etherphone: Collected Papers 1987-1988". Lixia
santi@ixos.UUCP (Michael Santifaller) (12/15/89)
There is this book with the proceedings of a LAN conference, its title is "Local Area Networks" I believe, and the editor is Tony West from Sun, who was with IBM in Geneva, then. It has been published in the early '80. The book contains several articles about LANs, obviously, including one by Shoch (??) about an experiment with voice over Ethernet (3MB Ethernet at that time). The whole article sounded very interesting and encouraging, since I had never believed that Ethernet was suitable for voice at all. Sorry, that I can't be of more help with the exact title and/or publisher. Michael
brian@ucsd.Edu (Brian Kantor) (12/17/89)
Not directly relevant, but it's proven to be quite easy to wire a telephone handset to my SparcStation and talk across the building over the ethernet using the CODEC chip that's built in the SS1. The delay is a bit like a satellite link and completely controllable by adjusting the buffering size. It even has sidetone. It's lots of fun to rcp into a coworker's machine and suddenly his workstation starts saying "Toto, I've a feeling we're not in Kansas anymore!" Anyone attempting to do this as a serious hack must consider a squelch algorithm so that you're not sending lots of zero-volume packets across the Ethernet. No doubt I'll soon get a nastygram from someone for adding to the traffic on the internet.... - Brian
pogran@CCQ.BBN.COM (Ken Pogran) (12/18/89)
A recent posting mentioned a paper presented by John Shoch in
1980 on carrying voice traffic over Ethernet. I happen to have a
copy of the conference proceedings, so here's the complete
bibliographic reference:
J. F. Shoch, "Carrying Voice Traffic thorugh an Ethernet
Local Network: A General Overview," in: "Local Networks for
Computer Communications; Proceedings of the IFIP Working
Group 6.4 International Workshop on Local Networks," edited
by Anthony West and Phillipe Janson; North-Holland
Publishing Company, 1981. ISBN: 0 444 86287 0
P.S.: the experiments were done over the original 3 Mb/s
ETHERNET.
Ken Pogranhlison@bbn.com (Herb Lison) (12/18/89)
santi@ixos.UUCP (Michael Santifaller) writes: > There is this book with the proceedings of a LAN conference, > its title is "Local Area Networks" I believe, and the editor > is Tony West from Sun, who was with IBM in Geneva, then. > It has been published in the early '80. The book contains several > articles about LANs, obviously, including one by Shoch (??) about > an experiment with voice over Ethernet (3MB Ethernet at that time). > The whole article sounded very interesting and encouraging, > since I had never believed that Ethernet was suitable for > voice at all. As part of our commercial software development, we implemented a voice capability in our BBN/Slate software package which makes use of a voice server in an IBM PC, accessed over the ethernet via the Sun PC-NFS TCP/IP toolkit. The voice server uses about 32kbs, and so far, performance does not seem to be a problem, even on a loaded network. Herb Lison
blais@ut-emx.UUCP (Donald Blais) (12/19/89)
In article <382@ixos.UUCP> santi@ixos.UUCP (Michael Santifaller) writes: > There is this book with the proceedings of a LAN conference, > its title is "Local Area Networks" I believe, and the editor > is Tony West from Sun, who was with IBM in Geneva, then. > It has been published in the early '80. The book contains several > articles about LANs, obviously, including one by Shoch (??) about > an experiment with voice over Ethernet (3MB Ethernet at that time). From UTCAT (UTexas online card catalog)... Local networks for computer communications: proceedings of the IFIP Working Group 6.4 International Workshop on Local Networks, organized by IBM, Zurich, Switzerland, August 27-29, 1980 /edited by Anthony West and Philippe Janson. Amsterdam; New York: North-Holland, 1981. -- Donald E. Blais INTERNET: blais@emx.utexas.edu Computation Center BITNET: BLAIS@UTAIVC University of Texas UUCP: ... !cs.utexas.edu!ut-emx!blais Austin TX 78712 PHONE: (512) 471-3241
brian@ucsd.Edu (Brian Kantor) (12/20/89)
Enough people have written to me to ask about using the SparcStation to transmit audio that I figured I'd better stem the flow by publishing the note here. First of all, the wiring diagram for the SS1 audio plug is in the 4.0.3 release manual that came with the SS1. You need an 8-pin mini-din plug which can be kinda hard to find, but it's used by Macintoshes so check with your local toy computer store. Note that the chip used in the SS1 is a telephony chip (it's an AMD AM79C30, designed to be the audio processor in an ISDN voice phone) so it hasn't got a lot of input gain. You'll need a high-output microphone. I used a carbon mic with a battery and a small transformer. I've also run the line-level output of my desk stereo into the SS1; again, I used a small audio transformer to avoid ground hum and frying the codec chip. The software I used is rsh hostname cat \> /dev/audio < /dev/audio which gives about a 1-second propagation delay on our local Ethernet; I suppose this is related to an 8k buffer in either rsh or cat (I haven't looked). When it's running, I'm sending a packet just about once a second, which is so little traffic that I stopped worrying about it there. For duplex communication, I suppose you'd want to use something else that uses a smaller buffer to get less delay. - Brian