Path: utzoo!mnetor!uunet!husc6!think!ames!ucbcad!ucbvax!csc-lons.csv001.tv.ARPA!scottr
From: scottr@csc-lons.csv001.tv.ARPA (Scott W. Rogers)
Newsgroups: comp.protocols.tcp-ip
Subject: TCP/SMTP ULTRIX <-> MULTICS PROBLEM
Message-ID: <8712301724.AA08788@csc-lons.ARPA>
Date: 30 Dec 87 17:24:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The ARPA Internet
Lines: 38


 I'm having a problem receiving some (SMTP) mail from a MULTICS host on
 my ULTRIX 1.2 and 2.0 (binary, sigh) VAX 8600 and 8650 systems.

 I can send mail to MULTICS without any problem, and most mail is
 received.  The problem is as follows:

    After the SMTP initialization, MULTICS sends a 51 character 'MAIL
    From: <username.mailbox.qualification.etc>' string which is never
    acknowledged by ULTRIX.  The MULTICS engineer says that his system
    is not receiving the TCP ACK even after several retrys and changing
    his timeout from 1 to 2 minutes.

    ULTRIX nevers sees the connection drop, and sendmail hangs.

    The next time MULTICS mail is received (every 15 minutes), a new
    sendmail process is spawned, and the same problem occurs.  This
    quickly stuffs the process table full of sendmail processes.

    The problem is completely reproducable through MAIL.  Using TELNET,
    the Multics engineer was able to produce it only sometimes.

    Notes:  The same problem occurs with ULTRIX 2.0 over DDN thru 2
    PSN's and ULTRIX 1.2 when MULTICS is on the same PSN.  I don't know
    if this provides any great insight to anyone.

    Also, TELNET connections to MULTICS work, but tend to hang/drop
    after some period of time.  I'm not sure of the relation, but if
    the problem lies in the TCP/IP code ...   DEC, are you listening !

 If anyone has had similar problems, or has a solution, or even any
 idea's, please let me know.

				Thanks.

				    Scott W. Rogers
				    scottr@csc-lons.arpa
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