Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!ames!lll-tis!SUN.COM!pv From: pv@SUN.COM (Peter Vanderbilt) Newsgroups: comp.protocols.iso.x400.gateway Subject: Re: Proposed delta to RFC 987 Message-ID: <8807061805.AA24532@polya.sun.com> Date: 6 Jul 88 18:05:57 GMT Sender: root@tis.llnl.gov Distribution: inet Organization: The Internet Lines: 34 Approved: post-x400-gateway@tis.llnl.gov I think the header/envelope distinction is important. There are two uses of source routes: (a) for testing and measurement and (b) to compensate for limited routing knowledge. Compensating for limited routing knowledge is such a swamp that it's not at all clear that we could do the right thing even if we wanted to; I would vote that we put our efforts into getting the routing knowledge distributed correctly and modify RFC 987 to say that all source route info is removed from header addresses before translation. But for (a), it does make sense to allow for source routing in the envelope -- an X.400 administrator should be able to add routing info to the envelope's recipient addresses to control the path that a message takes (like through the gateway and back or use the Internet for some of the hops). To accomplish this, we need only handle source routes in the envelope. Your mail transport system may do this already because some systems forward by adding an "@gateway:" (or "...%...@gateway") to envelope addresses (so your system would have to strip the "@gateway"). Actually, forwarding as described above is a third legitimate use of source routes -- if my 822 system (sendmail) wants to forward through X.400 to another 822 system, it does so by prepending "@gateway2:" to the recipient's address (where gateway2 is the 822 address of the remote gateway) and passing the message to the local gateway. What we need to define is what source routes we allow for in recipient addresses (P1.recipient ORNames with rfc-822 DDA's). Do we allow for 822-style "@host1,@host2,...:user@hostn" or the informal "user%hostn%...%host2@host1" or both? Must host1 be the destination gateway's 822 address or must host1 *not* be the destination gateway's 822 address or doesn't it matter? My answers are "both" and "doesn't matter" respectively. Pete