Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!mcnc!ece-csc!ncrcae!ncr-sd!hp-sdd!hplabs!ucbvax!UDEL.EDU!Mills From: Mills@UDEL.EDU Newsgroups: comp.protocols.tcp-ip Subject: Re: Internet Protocol #77 Message-ID: <8707131311.a011655@Huey.UDEL.EDU> Date: Mon, 13-Jul-87 13:11:50 EDT Article-I.D.: Huey.8707131311.a011655 Posted: Mon Jul 13 13:11:50 1987 Date-Received: Wed, 15-Jul-87 00:41:46 EDT Sender: daemon@ucbvax.BERKELEY.EDU Distribution: world Organization: The ARPA Internet Lines: 22 Chris, Is "protocol number 77" expressed in octal or decimal? Protocol number 63 (decimal) or 77 (octal) is reserved for local use, according to the assigned- numbers list. My interpretation of this is that gateways should not forward IPgrams carrying this number, so the NSFNET Backbone gateways, at least, do not; therefore, your traffic certianly did not rumble that way. Having said this, I am somewhat concerned about loopback and other things intended to have only local relevance and "never escape the local net." Some things, in particular local routing information and local broadcasts seem in tune with this notion, since they depend on addressing independent of local-network characteristics. However, some others (ND, NFS?) depend on the characteristics of the local net (delay, discard rate, etc.) as an intrinsic requirement for acceptable service. The use of addressing scope to delimit service range in such cases seems conuterproductive. What you really want is scope determined by maximum acceptable delay; in other words, some mapping of type-of-service plus maybe a new IP option. This is the same thing needed for packet speech and, in fact, implemented in those gateways supporting the Stream (ST) Protocol. Dave