info-vax@ucbvax.ARPA (04/14/85)
From: Richard Nelson <nelson@uci-icse> We need to know if it is possible to have 3 protocols running on the same cable: Decnet, TCP/IP, and XNA. Has anyone done it? Are there any articles/publications, etc. Thanks Richard Nelson
info-vax@ucbvax.ARPA (04/15/85)
From: Richard Garland <OC.GARLAND%CU20B@COLUMBIA.ARPA> AT the last DECUS DEC had DECnet, TCP/IP, and LAT-11 running on one ethernet. It all seemed to work. Rg -------
info-vax@ucbvax.ARPA (04/16/85)
From: (Stephen Tihor) <TIHOR@NYU-CMCL1.ARPA> We certainly are. We even have them sharing a single DEUNA on the VMS systems. \\ Stephen Tihor / CIMS / NYU / 251 Mercer Street / New York, NY 10012 // (( DEC Enet: RHEA::DECWRL::"""TIHOR@NYU-CMCL1.ARPA""" NYUnet: TIHOR.CMCL1 )) // ARPAnet: Tihor@NYU-CMCL1 UUCPnet address: ...!ihnp4!cmcl2!cmcl1!tihor \\ -------
info-vax@ucbvax.ARPA (04/19/85)
From: Jeffrey R. Del Papa <DP@MIT-MC> it is fully possible to have several protocols on one peice of coax. at lmi we have chaosnet, tcp/ip, and xns all on the same wire. the only problem comes with the new ethernet ieee standard for packet format. under the old 802.2 you have 6 bytes of destination ether address, 6 bytes of source ether address and a 2 byte type code. under the new 802.3, you have the 12 bytes of address, followed by two bytes of length information. there is a type field somewhere, but it means all the protocols will have to have the transport layer changed, and it isn't possible to run both protocols on the same wire. so much for standards .... jeff
info-vax@ucbvax.ARPA (04/23/85)
From: nbires!mccallum@BERKELEY (Doug McCallum) >comes with the new ethernet ieee standard for packet format. under the >old 802.2 you have 6 bytes of destination ether address, 6 bytes of source >ether address and a 2 byte type code. under the new 802.3, you have >the 12 bytes of address, followed by two bytes of length information. >there is a type field somewhere, but it means all the protocols will have Don't confuse 802.2 with being an old version of 802.3. IEEE standard 802.2 specifies a Logical Link Protocol to be used with the 802 family of access methods. 802.3 describes a media access method (CSMA/CD). Ethernet Versions 1.0 and 2.0 specify 6 bytes destination address, 6 bytes source address and 2 bytes of type. IEEE 802.3 specifies 6 bytes of destination, 6 bytes of source and 2 bytes of length. XEROX has reserved all valid IEEE lengths as IEEE specific types. It is possible to mix both versions on a given network. If the 802.2 protocol is not used with an 802.3 network, you have an ethernet version 2.0 type network. As an example, the IP type value for ethernet is 800(hex). This value does not correspond to a valid IEEE length. If the value in the type field (length field) corresponds to a valid IEEE length, then an IEEE 802.2 header comes next and can be distinguished from an IP field. >to have the transport layer changed, and it isn't possible to run both >protocols on the same wire. so much for standards .... The transport layer would need no changes, just the link layer and then it isn't that much of a change. Doug McCallum NBI, Inc. {attunix, ucbvax, ut-sally, hao}!nbires!mccallum
info-vax@ucbvax.ARPA (04/25/85)
From: dual!fortune!redwood!rpw3@BERKELEY (Rob Warnock) +--------------- | From: Jeffrey R. Del Papa <DP@MIT-MC> | ...ether address and a 2 byte type code. under the new 802.3, you have | the 12 bytes of address, followed by two bytes of length information. | there is a type field somewhere, but it means all the protocols will have | to have the transport layer changed, and it isn't possible to run both | protocols on the same wire. so much for standards .... | | jeff +--------------- Note that at least for Xerox-registered Ethernet frame types, there is no conflict between values in "Ethernet" type fields and "IEEE 802.3" length fields -- the range of values is disjoint. That is, all of the official Xerox types have values which are illegal (out of range) 802.3 types. Xerox has registered all of the legal 802.3 "length field" values (46-1500) as "types", so XNS drivers will not complain about 802.3 packets (and indeed may be able to handle them as "private" types). Thus, as long as 802.3 controllers do not barf too badly when receiving "bad" length fields, XNS and 802.3 can easily share a single cable. (However, this may not be true for various Berkeley types, such as "trailers". I haven't checked.) Rob Warnock Systems Architecture Consultant UUCP: {ihnp4,ucbvax!dual}!fortune!redwood!rpw3 DDD: (415)572-2607 USPS: 510 Trinidad Lane, Foster City, CA 94404
info-vax@ucbvax.ARPA (04/27/85)
From: Jeffrey R. Del Papa <DP@MIT-MC> chaosnet uses type 0X0408 for packets, and 0X0608 for address resolution... this is within the range of legal lengths... (0X060E)... jeff