Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!amdcad!ames!ucbcad!ucbvax!AI.AI.MIT.EDU!JBVB From: JBVB@AI.AI.MIT.EDU ("James B. VanBokkelen") Newsgroups: comp.protocols.tcp-ip Subject: Re: ... Transmission of IP Datagrams over IEEE 802 ... Message-ID: <273298.871023.JBVB@AI.AI.MIT.EDU> Date: Fri, 23-Oct-87 00:29:16 EST Article-I.D.: AI.273298.871023.JBVB Posted: Fri Oct 23 00:29:16 1987 Date-Received: Sun, 25-Oct-87 13:27:34 EST Sender: operator@ucbvax.BERKELEY.EDU Organization: The ARPA Internet Lines: 16 Well, one of the problems here is that IBM has defined 802.5, more or less, and they seem to have felt they wanted to sell: 1) MAC-level bridges that don't learn connectivity like Ethernet bridges do, instead requiring that packets be source-routed, and 2) MAC-level bridges which can only hack datagrams about 1/10th the size of the MTU of the connected LANs. Given that they are still successfully selling EBCDIC architectures, I'm not sure what we can do besides document what they have legislated. So, ARP and related MAC-level routing schemes take a nasty hit, and useful MAC-level transparency amongst 802.x LANs becomes much harder to achieve. Anyway, at the 802.2 level, the encapsulation is indeed identical. As Greg has pointed out, 802.2 is LLC, not MAC. jbvb