Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!tank!ux1.cso.uiuc.edu!ux1.cso.uiuc.edu!uxh.cso.uiuc.edu!carlson From: carlson@uxh.cso.uiuc.edu Newsgroups: comp.protocols.tcp-ip Subject: Re: MXing the world (was RE: New H Message-ID: <16300008@uxh.cso.uiuc.edu> Date: 12 Nov 89 04:38:00 GMT References: <2029@cmx.npac.syr.edu> Lines: 43 Nf-ID: #R:cmx.npac.syr.edu:2029:uxh.cso.uiuc.edu:16300008:000:2111 Nf-From: uxh.cso.uiuc.edu!carlson Nov 11 22:38:00 1989 By: jmwobus@cmx.npac.syr.edu Nov 10, 1989 [ stuff about UUCP deleted ] >It would be neat if mail software could automatically find the >nearest public gateway to BITNET. The DNS doesn't deal >with concepts like "nearest", but IP routing tables do. This is the crucial point. IP routine minimizes travel time (and travail) for IP packets. UUCP (I think) also optimizes routes. DNS was, of course, is designed for a different purpose, and was not intended to duplicate the functionallity of IP routing. DNS seemed like a good place to put MX translation, and it works fine for Internet mail, since Autonomous Sites and MX handlers corrolelate very well with geographical/topological regions. >However, one could imagine a system by which >a single packet uses the routing table to find the nearest gateway, >an answer from the gateway tells the sender what the gateway's >(normal) IP address is and then the SMTP session starts after that. One hitch is that it sounds like "nearest foriegn gateway" information would have to be encoded in every new routing protocol that comes along. (Though it might just be worth the trouble.) What I think is really needed is for the IP protocol to have some concept of foreign destinations. Perhaps a Class D (Multi-cast) address could be reserved for the meaning of "Nearest Bitnet Gateway", and gateway hosts would advertise themselves as such. I am not up on the details of multicasting, but sounds like this capability could implement what John suggests. Hosts wishing to send to the .Bitnet domain could skip DNS tables and query IP routers with a special request packet. This way, Non-IP mail could be properly routed based on distance. This would of course require fundemental additions to the IP protocol (disturbing to purists), but mail service is so central to the use and growth of the network that perhaps someone should give it some serious though. >John Wobus -- Syracuse University -------------------- Brad Carlson or University of Illinois -- Consultant -- NeXT guru -- Windows Programmer