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From: djb@cbosgd.UUCP (David J. Bryant)
Newsgroups: net.lan
Subject: Re: HP's TCP/IP implementation
Message-ID: <260@cbosgd.UUCP>
Date: Wed, 29-Aug-84 09:53:25 EDT
Article-I.D.: cbosgd.260
Posted: Wed Aug 29 09:53:25 1984
Date-Received: Thu, 30-Aug-84 02:46:05 EDT
Organization: AT&T Bell Laboratories, Columbus
Lines: 44

We have had several meetings with a variety of HP people about this issue
recently.  You are quite right - the HP implementation of TCP/IP is different
from the standard TCP/IP, and it's intentional on HP's part.  As far as I
understand the situation the differences are that HP's version does not
provide/support the following:

 	1) Urgent Data
        2) Graceful Release
        3) Option Fields
        4) Segmentation and Reassembly of IP packets.
        5) Checksumming. (HP figures that this is done adequately in layer 2,
	   so they left it out to improve performance)
        6) Address-Resolution Protocol.  HP uses a custom-designed "probe"
	   mechanism.

The bottom line is that an HP TCP/IP system can ONLY talk to another HP
TCP/IP product!  We found this to be an incredible design decision, and
one that is totally incompatible with our requirements.

Further, HP supports only file transfer and remote file access.  Virtual
terminal and IPC applications are planned for the future. Yet another
problem area we're having to work out...

According to HP, they have had "several people" question their lack of
support for standard TCP/IP.  They are clearly aware of the problem, and 
are considering fixing things up, but we have not had any detailed
committment from them.  For some reason they are determined to support
their "version" of TCP/IP, but they are talking about some mechanism
that will make it possible to talk both their version and the standard
version with the same software.  Regardless, I expect that things will
get fixed eventually - the HP folks have been amazingly receptive to
our requests so far - but it will take time.

Still, we see this as a silly situation, and have yet to understand HP's
reasoning on this one.  I'd like to personally encourage every HP owner/user 
(and anyone else that can get HP's ear) to strongly "suggest" to their HP 
contact that HP get their TCP/IP version in line with the standard, for
innumerable obvious reasons.

As our discussions with HP progress and new things happen, I'll keep you 
posted.

	David Bryant   AT&T Bell Laboratories   Columbus, OH   (614) 860-4516
	(cbosgd!djb)