Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site ucbvax.BERKELEY.EDU Path: utzoo!watmath!clyde!cbosgd!ucbvax!red.rutgers.edu!HEDRICK From: HEDRICK@RED.RUTGERS.EDU (Charles Hedrick) Newsgroups: mod.protocols.tcp-ip Subject: Re: Zero window probes Message-ID: <12158537451.44.HEDRICK@RED.RUTGERS.EDU> Date: Mon, 11-Nov-85 22:20:59 EST Article-I.D.: RED.12158537451.44.HEDRICK Posted: Mon Nov 11 22:20:59 1985 Date-Received: Wed, 13-Nov-85 06:57:47 EST References: <851108205728.000456@CISL-SERVICE-MULTICS.ARPA> Sender: daemon@ucbvax.BERKELEY.EDU Organization: The ARPA Internet Lines: 22 Approved: tcp-ip@ucbvax.berkeley.edu If this is what I think it is, I think it depends upon the application. If you are a TCP user process, and the other end doesn't accept any data in 5 minutes, there is probably something wrong. But suppose you are a print spooler talking to a remote printer. We have a situation just like that. When the printer runs out of paper, or is otherwise in need of attention, it XOFF's the connection. Eventually, the result is that TCP refuses to accept any data. The operator may take a long time to get to this. We'd like to keep the connection open as long as necessary. Similarly, consider the connection between a host and one of our terminal servers. The terminal server allows a user to have several connections open at once. However the terminal is connected to only one session at a time. There are commands to let you go back and forth between connections. Obviously the server has only a finite buffer. When you are not connected to a session, and its buffer fills, TCP will stop accepting data. Again, we would like the host to keep the connection open indefinitely. Currently TOPS-20 will time out after a certain time. Our users all consider this to be a bug. They are annoyed when they reconnect to a TOPS-20 session and find that TOPS-20 has given up. -------