[8687] in Commercialization & Privatization of the Internet
Re: One-way Internet?..no, it's "Asymetric"
daemon@ATHENA.MIT.EDU (Dick St.Peters)
Tue Nov 30 16:12:24 1993
Date: Tue, 30 Nov 93 16:01:26 EST
From: stpeters@spare-parts.crd.ge.com (Dick St.Peters)
To: smith@sfu.ca
Cc: com-priv@psi.com
> From: smith@sfu.ca (Richard Smith)
>
> Related to my comments yesterday on the Hybrid Networks
> ...
>
> Perhaps this has been debated already here, but what are the
> advantages/disadvantages of this sort of asymetric transport? The
> advantages I see include being able to provide higher bandwidth to more
> people. The disadvantage is that the internet moves to a broadcast model,
> with all the qualities that implies.
Yes, we have been over all this before, and no, broadcasting is NOT
what these models are about.
Some examples where the assymmetric model works well:
a radiologist types in a few dozen characters specifying an
image he/she wants, and a megabyte of image data comes in.
a mosaic user intermittently clicks on menus, causing a few
bytes to be sent out and hundreds or thousdands of bytes to
flow in.
an ftp user types a few characters to log in and request a
file, and a megabyte tarfile is sent to him/her.
a user runs an X graphics program; he/she sends a few typed
characters and mouse events out and gets large amounts of
graphics data back.
The last case is instructive: someone with a keyboard and mouse trying
deliberately to generate as much stuff to send as possible can generate
only a couple of hundred *bits* per second, and you really have to work
at it to do that.
To computers and networks, people are simply impossibly slow devices.
They spend most of their time just waiting for us to *do* something.
If you are not pouring out data at computer speeds - aren't an
information *provider*, you don't need much bandwidth going out. The
great majority of computers on a network - most any network - slurp a
lot more data off the network than they put on it. For a computer on
the Internet, most of what goes out is TCP acks.
Many of us would like to be providers as well - I run http and gopher
servers on my own machine, but on our site LAN with 10 Mbps symmetric
bandwidth everywhere, hardly anybody uses the outgoing bandwidth for
anything.
The assymmetric model is less than perfect, but it's lot better than
most of us have now, and it uses wiring that already exists almost
everywhere: cable in and telephone out.
--
Dick St.Peters
GE Corporate R&D, Schenectady, NY stpeters@dawn.crd.ge.com
