[2239] in Commercialization & Privatization of the Internet
Re: SLIPing Questions and Answers
daemon@ATHENA.MIT.EDU (Pushpendra Mohta)
Sun Feb 2 05:06:25 1992
From: Pushpendra Mohta <pushp@CERF.NET>
To: marc@MIT.EDU
Date: Sun, 2 Feb 92 2:04:36 PST
Cc: bzs@world.std.com, com-priv@psi.com, cook@tmn.com
In-Reply-To: <9202020820.AA09981@portnoy.MIT.EDU>; from "Marc Horowitz" at Feb 2, 92 3:20 am
Marc Horowitz writes:
>>
>>>> I proposed a model which minimizes administration and could support
>>>> around 32 simultaneous sessions (depending on what's actually being
>>>> done) for a relatively low price, by using terminal servers across
>>>> 56kb lines. It could be easily duplicated for N*32 seats. But it
>>>> didn't involve any SLIP. Local hardware and administration is
>>>> minimized.
>>
>>For real interactive use, I don't think the terminal server model is
>>right. I don't think having a local news/mail/foo server is right
>>either. The interface we want is something which gives you the ease
>>of running remotely, and the speed/power of running locally. In other
>>words, you need some very clever user interfaces, which I think would
>>run just as well over an IP link (SLIP/PPP/whatever). A serial link
>>running one application at a time doesn't cut it. It's natural for a
>>user to be reading news, and say, "I want the file mentioned in that
>>post", and start the transfer. Maybe it's slow, but if it runs while
>>you're doing something else, you don't care as much.
>>
>>I think the problem is that Barry is assuming that when someone says
>>"TCP/IP" they mean NNTP, SMTP, FTP, and all those other protocols
Certainly, multiplexing of applications over a serial IP link is a
BIG plus. However, it's not the primary reason "John Q. Public" choses
it primarily for. At least not in my experience.
One of the primary reasons many users prefer dialup IP over
plain terminal service is the ability to do a ONE-STEP file
transfer between Internet hosts and the machines on their desk/homes.
The alternative is to ftp it first to their "base" Internet connected
host and then download it using kermit/zmodem etc.
(Substitute IP for Internet where ever appropriate )
The other major reason is local mail processing and "transparent"
transfers using SMTP.
For all other purposes, they would much rather prefer terminal access
to a well administered host loaded with Internet "goodies".
And, if you are constrained to running vanilla SLIP, you might actually
lose on raw transfer rates. Interactive work, like reading news is
again much faster with plain terminal dialups. More than 200 msec
character echo delays ( not at all unusual on a 9600 dialup IP link )
start to get to you after a while. This is improving with
V.32bis/V.42/V.42bis modems .
The Internet (IP) savvy users prefer to use dialup IP because
(increasingly) they have a workstation at home just like the one
at work, and they *must* have the same environment at either location.
This is the user that likes to squeeze the last ounce of capacity
Shannon will allow, and considers multiplexing of applications a big
win.
(My arguments preclude organizations who use dial up IP to
connect their local IP nets to the Internet. They maintain a rich set
of local services )
Dialup IP is a win for most users.
Barry's model holds where the local site is unwilling or unable
to provide administration and where the kind of applications
run do not require much local processing or storage. In any event,
most terminal servers now provide the capability of dialup IP
and terminal service in the *same* box so Barry's suggestion
does not incur any additional *hardware* cost per se.
--pushpendra
Pushpendra Mohta pushp@cerf.net +1 619 534 5056
CERFNet
(Anyone else wonder why this is being discussed on comp-priv ? )
