Priscilla
I have a lot to learn from you (and others), and I mean that in all honesty.
Thank you for being so patient and understanding.
It's good to see the "real" you again.
-Anil





-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of
Priscilla Oppenheimer
Sent: Tuesday, December 11, 2001 8:00 PM
To: [EMAIL PROTECTED]
Subject: RE: Does session layer protocol use IP address ? [7:28378]


At 09:11 AM 12/11/01, anil wrote:
> >Please stop sending messages about this topic
> >(or any other topic) until you have done some real research.

I'm sorry I was so hard on you. You're right that I don't have a right to
tell you what to send. You irritated me because you kept sending links to
wrong info and I misunderstood your motive for doing that.

I gave more thought to NFS and the issue of wrong info everywhere. I stick
to my guns that you have to dig deeper sometimes and investigate the
messages that the protocol sends, the services it offers, the services
below it that it uses, what problem the creators of the protocol were
trying to solve, etc. Knowing (or investigating) some history helps.

Sun developed NFS as part of their Open Network Computing platform in the
late 1980s. The OSI model was already being used for what it's good for.
NFS was designed to be an application-layer protocol that ran above a
session-layer protocol and uses XDR at the presentation layer. This is not
a good one to turn into an arguable issue. It's straight forward.

Because it's a Sun protocol, I wasn't really sure if there was an RFC, but
there does seem to be one, RFC 1094. I found it by searching on "NFS RFC"
in Google. It was the first hit.

Regarding the existence of session-layer protocols, there really are very
few in the IP world. RPC is one. NetBIOS is one. AppleTalk has the
AppleTalk Session Protocol (ASP), but when Apple Filing Protocol (AFP) runs
above TCP, the session layer disappears. There is something called Data
Stream Identifier (DSI) between AFP and TCP, but it doesn't do much.

OSI did a good job of defining the session layer. Believe it or not, Cisco
Network Academy materials describe it reasonably well and cover two-way
alternating and two-way simultaneous relationships, etc. But then they
categorized the wrong protocols as being session-layer protocols. OSI's
definitions for the session layer are just academic these days. Even the
protocols I mentioned, such as NetBIOS, etc. don't behave the way OSI said
would!? ;-)

Priscilla


>I had no idea you were the moderator of this group.
>My sincere apologies
>
>-Anil
>


________________________

Priscilla Oppenheimer
http://www.priscilla.com




Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=13&t=28378
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