Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!ucbvax!VENERA.ISI.EDU!braden
From: braden@VENERA.ISI.EDU
Newsgroups: comp.protocols.tcp-ip
Subject: Re:  SO_KEEPALIVE considered harmful?
Message-ID: <8905241636.AA04568@braden.isi.edu>
Date: 24 May 89 16:36:22 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 16


I don't believe anyone has advocated that keep-alives are a bad thing...
indeed, they appear to be a necessity in an imperfect world.  The
controversy (for the past 10 years, at least!) is whether or not they
belong in TCP.  The decision of the TCP/IP developers was that 
keepalives ought to be in the application layer, not the transport layer.

Each application has its own parameters for keepalive.  Furthermore,
cautious application implementors may already have application-level
keepalives, and economy of protocol mechanism argues for having the
functionality at only one level.  On the other hand, one can (and
some people do) argue that economy of mechanism requires that TCP
provide a keepalive mechanism that may be invoked and parametrized
by an application.  The Host Requirements RFC explicitly allows that. 

Bob Braden