Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!ingr!b11!guy!guy
From: guy@guy.uucp (Guy Streeter)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: TCP Urgent Data Handling
Message-ID: <6052@b11.ingr.com>
Date: 29 Sep 89 15:08:27 GMT
References: <4982@omepd.UUCP> 
Sender: usenet@b11.ingr.com
Lines: 34

hedrick@geneva.rutgers.edu (Charles Hedrick) writes:
> ...
>Only the concept of "last urgent byte" makes any sense, and with the
>off by one fiasco, even that is ambiguous.  I would suggest that you
>*not* try to "clarify" urgent, but stick with the 4.3 semantics.
> ...

RFC 1011 - Official Internet Protocols                          May 1987


         Urgent:  Page 17 is wrong.  The urgent pointer points to the
         last octet of urgent data (not to the first octet of non-urgent
         data).

 ...

***DRAFT RFC***          TRANSPORT LAYER -- TCP            June 16, 1989

         4.2.2.4  Urgent Pointer: RFC-793 Section 3.1

            The second sentence is in error: the urgent pointer points
            to the sequence number of the LAST octet (not LAST+1) in a
            sequence of urgent data.

 ...

BSD 4.3 sets the urgent pointer to the LAST+1 octet in a sequence of urgent
data.  Whenever anyone else violates a protocol, the response in this
newsgroup is always "Fix your software!"  Should we propagate Berkeley's
error in the interest of compatibility, or should we do it right?

Guy Streeter
b11!guy!guy@ingr.com
...uunet!ingr!b11!guy!guy