Symbolics terminal emulator works lousy

["David L. Andre" <DLA@diamond.s4cc.symbolics.com>]

    Date: Fri, 18 Dec 87 12:57 EST
    From: Barry Margolin <barmar@Think.COM>

	Date: Fri, 18 Dec 87 09:38:42 +0100
	From: mcvax!jungfrau!ceb@uunet.uu.net

	a. When you reboot a Lispm and there are ftp sessions or telnet
	   sessions open, they get left around

    This is an aspect of the Telnet and TCP protocols.  There is no way to
    tell whether the host at the other end of an idle connection is really
    still there.  Connection problems only become apparent when a host
    actually tries to produce output; if TCP doesn't get an acknowledgement
    after a few retries it decides that the host or network is dead, and if
    it gets a TCP reset it means that the host has since rebooted or
    reinitialized TCP.  If the host doesn't delete the sessions when these
    happen, it is a bug in the software.  This is all intentional on the
    part of the TCP/IP designers; it eliminates network traffic due to
    packets being sent just to let the other guy know you're there, and it
    makes connections tolerant of temporary network problems.

    Some of the blame can be put on Symbolics.  When you reboot a Lispm, the
    processes that are running are not killed cleanly, so they can't close
    their connections.  SI:HALT doesn't kill processes because you might
    want to do a Continue from the FEP.  There is no command that I know of
    that does a clean shutdown.

Uh, how about Logout?

						    barmar