Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site peora.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!harvard!talcott!panda!genrad!decvax!tektronix!uw-beaver!cornell!vax135!petsd!peora!jer From: jer@peora.UUCP (J. Eric Roskos) Newsgroups: net.mail Subject: Re: Mail routing -- problems showing up Message-ID: <1431@peora.UUCP> Date: Mon, 5-Aug-85 08:46:07 EDT Article-I.D.: peora.1431 Posted: Mon Aug 5 08:46:07 1985 Date-Received: Sat, 10-Aug-85 23:38:53 EDT References: <3018@nsc.UUCP> <2875@topaz.ARPA> <4787@mit-eddie.UUCP> <1022@sdcsvax.UUCP> Organization: Perkin-Elmer SDC, Orlando, Fl. Lines: 65 > For example, suppose I'm a non-UUCP arpa site that wants to send to > ihnp4!cbosgd!mark. I could write this as > ihnp4!cbosgd!mark@BERKELEY > Of course, mark might have to reply > ihnp4!ucbvax!myname@mysite.ARPA (excuse me, the name is changed) > So far, no good--the "@" has top precedence in the 1st example, > lowest in the 2nd. Why? Who says that Mark has to write paths with the same syntax you do? [We're assuming that for some reason Mark actually wants to write the path, instead of an address -- which may well be a valid assumption sometimes.] Without getting into endless repetition, it is perfectly reasonable that on your "non-uucp" network, "@" might have precedence over "!". It is also perfectly reasonable that "!" might have precedence over "@" on Mark's. It is only unreasonable when, for some reason, you require a uniform path language for both networks. > However, why couldn't these two be: > berkeley!ihnp4!cbosgd!mark > ihnp4!berkeley!mysite!myname > > The first is completely compatible with every UUCP site in the world. Because the latter example requires that "berkeley" know how to translate "mysite!myname" into a routing or addressing format that is correct for your network. This is especially hard when the destination site is not on the network the UUCP gateway connects to -- i.e., when an intermediate network has to be used to get to the final destination network. By way of example, consider the following. Suppose I am on UUCP. There is another network -- and let's say it's some sort of secret network you at the UUCP gateway can't get the specifications for -- that is gatewayed to the ARPAnet. Now, how would Berkeley know that ihnp4!berkeley!nudet.ABC!gmas was to be translated to seclia##tnwmon#nudet#gmas@ABC-GW.MIL Furthermore, suppose ABC-GW.ARPA doesn't really care about UUCP at all. So you can't send them nudet.ABC!gmas@ABC-GW.ARPA and expect them to convert the UUCP address for you. (I.e., ihnp4!berkeley!abc-gw.MIL!nudet.ABC!gmas would not work for this reason.) Having them do this would require that they acknowledge sufficient importance of the UUCP network (or of the sender) to invest the effort to make ABC-GW recognize nudet.ABC!gmas and translate it appropriately -- something they may well not be willing to do. The point is, the amount of knowledge required by UUCP gateways is substantially increased if you require gateways to translate pure-UUCP paths into acceptable paths (or just addresses) for arbitrary other- gateways, especially if the destination address is not on a network directly accessible to UUCP. Alternately, it requires that non-UUCP gateways into other networks have knowledge of the UUCP addressing syntax. (The difference being that in the first case, your UUCP gateway generates the complete address as it would appear on the network you are gatewaying onto; in the latter case, you just put the leftover part of your UUCP path into the local-part of the address for the next gateway down the line and require it to make the translation.) -- Shyy-Anzr: J. Eric Roskos UUCP: ..!{decvax,ucbvax,ihnp4}!vax135!petsd!peora!jer US Mail: MS 795; Perkin-Elmer SDC; 2486 Sand Lake Road, Orlando, FL 32809-7642 "Frr ubj Tbq jvgu uvf yvtugavat nyjnlf fzvgrf gur ovttre navznyf, naq jvyy abg fhssre gurz gb jnk vafbyrag; juvyr gurfr bs n yrffre ohyx punsr uvz abg." -- Negnonavf