Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site wdl1.UUCP
Path: utzoo!linus!decvax!decwrl!greipa!pesnta!hplabs!hpda!fortune!wdl1!jbn
From: jbn@wdl1.UUCP
Newsgroups: net.dcom
Subject: Re: Packetized Voice
Message-ID: <438@wdl1.UUCP>
Date: Thu, 23-May-85 21:22:17 EDT
Article-I.D.: wdl1.438
Posted: Thu May 23 21:22:17 1985
Date-Received: Mon, 27-May-85 03:12:26 EDT
Sender: notes@wdl1.UUCP
Organization: Ford Aerospace, Western Development Laboratories
Lines: 19
Nf-ID: #R:ttidcb:-35400:wdl1:11700017:000:1065
Nf-From: wdl1!jbn    May 23 13:23:00 1985

> Not true. Packet voice offers two main advantages over circuit-switched voice.
> First, it requires less than 40% of the bandwidth, since there is no need
> to tie up the channel during silent periods. Second, it integrates voice and
> data in a single communication network.

       The TASI subchannel-assignment system used on transoceanic cables
for decades avoids tying up the channel during silent periods, and achieves
roughly similar bandwidth economy.  And most newer switching systems,
especially PBXes, are digital circuit switches and handle both voice and data
in a similar way.  You don't need packet switching to achieve these gains.
       It's interesting to hear that Bell Labs tried to build a big packet
network.  I would appreciate references, if available.  To date, all packet
networks have been tiny by telephony standards, and no one has convincingly
demonstrated that packet switching technology can be scaled up to networks
with millions of subscribers.  Most of the X.25-based systems are circuit
switches underneath.

					John Nagle