Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!know!samsung!zaphod.mps.ohio-state.edu!wuarchive!decwrl!sgi!rpw3@rigden.wpd.sgi.com From: rpw3@rigden.wpd.sgi.com (Rob Warnock) Newsgroups: comp.protocols.tcp-ip Subject: Re: Beginner's info TCP & UDP Message-ID: <64291@sgi.sgi.com> Date: 17 Jul 90 03:41:27 GMT References: <81247@srcsip.UUCP> Sender: rpw3@rigden.wpd.sgi.com Reply-To: rpw3@sgi.com (Rob Warnock) Organization: Silicon Graphics, Inc., Mountain View, CA Lines: 29 In answering a beginner's question, hedrick@athos.rutgers.edu (Charles Hedrick) writes: +--------------- | People tend to use UDP where (1) they plan to be making isolated | queries, such that the overhead packets used to set up and close a | connection would form most of the traffic (2) they need more | performance than they think they can get from TCP.... +--------------- I would add: ...(3) there are a very large number of clients accessing a single server, such that the cost of holding a connection open for each active client would be excessive. [The definition of "excessive" is system- and application-dependent.] In some sense this is the same as Hedrick's #1, except that #1 refers to conserving dynamic network bandwidth, and #3 to conserving quasi- static server system resources "wired-down" by connections (sockets, open-file slots, processes, etc.). -Rob ----- Rob Warnock, MS-9U/510 rpw3@sgi.com rpw3@pei.com Silicon Graphics, Inc. (415)335-1673 Protocol Engines, Inc. 2011 N. Shoreline Blvd. Mountain View, CA 94039-7311