Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site decvax.UUCP Path: utzoo!linus!decvax!jmcg From: jmcg@decvax.UUCP (Jim McGinness) Newsgroups: net.mail Subject: Re: Smart routing Message-ID: <381@decvax.UUCP> Date: Sun, 19-Feb-84 04:05:46 EST Article-I.D.: decvax.381 Posted: Sun Feb 19 04:05:46 1984 Date-Received: Sun, 19-Feb-84 08:22:08 EST References: <5524@decwrl.UUCP> Organization: DEC UNIX Engineering Group Lines: 28 As perpetrator of the path improver in use on decvax, sophomoric as it may be, I feel compelled to say a few words in its defense. Under the circumstances, it's probably just as well that I cannot remember who first suggested this method. The path improver short circuits paths containing a uucp neighbor. For example, the path "siteA!siteB!siteC!user" is truncated to "siteC!user" if decvax has talked to siteC recently. Uucp (not just our version) keeps a stats file containing, for each site, the time of the most recent conversation or transfer. The important qualities of this method are that it is local, automatic, fairly safe, and uniform. All of the information needed is available on the machine doing the routing. There is no database to be collected and maintained. Mail will not be mis-directed along paths that have fallen inactive nor redirected into loops. If everyone used it, it would work even better. It does have failings. If it finds "vortex" in the path, then that piece of mail will go to LA rather than to the E-net. If someone sends mail on a long loop to probe a path or provoke a poll, it will get bounced at decvax rather than having the desired effect. It doesn't save us any money, just that of those sites we trim out of paths. Jim McGinness decvax!jmcg Digital Equipment Corp. (603)844-5703 MKO2-1/H10 Merrimack, NH, 03054