dlb@abic.UUCP (David Bernard) (02/12/86)
*** REPLACE THIS LINE WITH YOUR MESSAGE ***
I am interested in a gateway/bridge product that will provide
a link between IEEE 802.3 & 802.4 networks.
Does anyone have knowledge of such a product? I understand that
Bridge Communications and DEC have an offering along this line.
Does anyone have actual experience in the use of such a product
from any vendors?
Thanks very much,
Dave Bernard
Allen-Bradley Co.
Division of Rockwell Int'l.
Bldg 3E 747 Alpha Dr.
Highland Hts., OH 44143
(216) 449-6700 x5222
decvax!abic!dlb skip@ubvax.UUCP (Skip Addison Jr) (02/13/86)
In article <733@abic.UUCP> dlb@abic.UUCP (David Bernard) writes: > I am interested in a gateway/bridge product that will provide > a link between IEEE 802.3 & 802.4 networks. > > Does anyone have knowledge of such a product? I understand that > Bridge Communications and DEC have an offering along this line. > ... > Dave Bernard > Allen-Bradley Co. > decvax!abic!dlb Bridges get involved at the network layer. IEEE 802.3 & 802.4 only specify up through the data link layer. What bridge you need depends on what network layer protocols you need. For example, Ungermann-Bass provides networks based on a variety of different protocols. Which bridge software you get depends on which network protocols you're using. Like Ungermann-Bass's, Bridge's and DEC's bridges will only work on networks that use their protocols. Fortunately, we've all started basing our products on standard protocols, so depending on your system, vendor A's network interface units may communicate using vendor B's bridges. Buffered repeaters do exist that don't know anything about layers higher than the data link layer. That may be what you want. Ungermann-Bass offers those, as does a company by the name of Veralink, if I remember right. For information on Ungermann-Bass's stuff you can contact me. I don't have an address or telephone number for Veralink, sorry. -- Skip Addison {lll-crg, decwrl, ihnp4}!amdcad!cae780!ubvax!skip Ungermann-Bass, Inc (408) 496-0111
gp@lll-crg.ARpA (George Pavel) (02/14/86)
Interactive Systems in Ann Arbor, Michigan has announced an 802.3 to 802.4
bridge or gateway that runs either ISO or TCP/IP protocols (I believe). They
used to be owned by 3M and are now owned by Allen-Bradley. They can be
reached at:
3920 Varsity Drive
Ann Arbor, MI 48104
(313) 973-1500
The product is called a LAN/II Network Bridge Unit. I have no experience
with the product.
George Pavel ARPANET/MILNET: gp@lll-crg
Lawrence Livermore National Laboratory UUCP: {ihnp4,seismo}!lll-crg!gp
P.O. Box 808 L-61
Livermore, CA 94550
(415)422-4262fwb@siemens.UUCP (02/14/86)
> I am interested in a gateway/bridge product that will provide > a link between IEEE 802.3 & 802.4 networks. Charles River Data Systems demonstrated such a system at AUTOFACT'85 in Detroit. It was a gateway between MAP (802.4) and TOP (802.3). I don't have any direct experience with the product, but I saw it work at the show. ----------------------------------------------------- Frederic W. Brehm (ihnp4!princeton!siemens!fwb) Siemens Research and Technology Laboratories 105 College Road East Princeton, NJ 08540 (609) 734-3336
sob@talcott.UUCP (Scott O Bradner) (02/16/86)
In article <440@ubvax.UUCP>, skip@ubvax.UUCP (Skip Addison Jr) writes: > ... Which > bridge software you get depends on which network protocols you're using. > Like Ungermann-Bass's, Bridge's and DEC's bridges will only work on > networks that use their protocols. DEC's bridge is protocol independant. we have one here that is running with DECnet and TCP/IP now and we will move it next week to a place that also uses XNS. no problems seen so far. scott bradner harvard university sob@harvard.{uucp,arpa,csnet,harvard.edu} sob@harvunxt.bitnet
mark@cbosgd.UUCP (Mark Horton) (02/17/86)
In article <440@ubvax.UUCP> skip@ubvax.UUCP (Skip Addison Jr) writes: >Bridges get involved at the network layer. IEEE 802.3 & 802.4 only >specify up through the data link layer. What bridge you need depends >on what network layer protocols you need. Perhaps we're working with different definitions, but according to my understanding of terms like "bridge", this is just plain wrong. You're saying that 802.3 only goes up through the data link layer, and at least one OSI person agrees with you, calling the 48 bit Ethernet address a way of handling a "multipoint data link layer" rather than a network layer. Personally, I think if it looks like a duck and quacks like a duck, it's a duck (or a good emulation), even if it didn't hatch from an official duck egg. I think Ethernet and 802.3 support a network layer, and the IP or CLNS or IDP layer above it is a sublayer of the same network layer above Ethernet. But you say that bridges work above what 802.2 provides, which seems to me that you're talking about the IP or CLNS et al layer. To me, this is not a bridge, it's a "gateway" or "packet router". In my book, an Ethernet bridge operates at the Ethernet (802.2) layer. It's much like a repeater with a buffer and some smarts about where to route Ethernet level packets (based on its knowledge about which segment the destination address is on.) These bridges can connect various 802.2 networks together, such as 802.3 Ethernet to 802.4, and even hook similar or different networks together with random virtual or physical circuits. Such bridges are, as one of their features, totally transparent to whatever protocols you may be running at the higher levels. Gateways work at the same level as their peers on other nodes, so the end to end protocols matter. Bridges do not have peers on the other side of the net, so they appear to not be there on the other end. Gateways operate pretty much at one level, and are built into the network architecture. Bridges understand any lower levels they are working with, so you can think of them as working at the next higher level. But this is still below the real next higher level; an Ethernet bridge in effect works in a layer above Ethernet but below IP. Incidently, is there a bridge between Ethernet (or 802.3) and Starlan available or in the works? Sure might be handy for cabling to run an Ethernet backbone trunk with Starlan into the offices, or on the other hand, to use Starlan for the building wiring (to reuse existing wiring) but to plug in boxes with an Ethernet interface. I'm thinking of something inexpensive - almost like an adaptor, not a big expensive general purpose bridge. Mark
schoff@rpics.uucp (Martin Schoffstall) (02/17/86)
> Bridges get involved at the network layer. IEEE 802.3 & 802.4 only Sorry, "bridges" as that word is used by DEC, the INTERNET world and other significant portions of the free world does NOT deal with the network layer. Only through the datalink layer. > specify up through the data link layer. What bridge you need depends > on what network layer protocols you need. For example, Ungermann-Bass > provides networks based on a variety of different protocols. Which > bridge software you get depends on which network protocols you're using. > Like Ungermann-Bass's, Bridge's and DEC's bridges will only work on > networks that use their protocols. Fortunately, we've all started basing Even a quick look at DEC's marketing literature, let alone a technical understanging show's that DEC's bridges are independant of protocol. Your posting is both wrong an a little commercial... -- marty schoffstall schoff%rpics.csnet@csnet-relay ARPA schoff@rpics CSNET seismo!rpics!schoff UUCP martin_schoffstall@TROY.NY.USA.NA.EARTH.SOL UNIVERSENET RPI Computer Science Department Troy, NY 12180 (518) 271-2654
skip@ubvax.UUCP (Skip Addison Jr) (02/18/86)
In article <1@rpics.uucp> schoff@rpics.uucp (Martin Schoffstall) writes: >> Bridges get involved at the network layer. IEEE 802.3 & 802.4 only > >Sorry, "bridges" as that word is used by DEC, the INTERNET world >and other significant portions of the free world does NOT deal >with the network layer. Only through the datalink layer. > ... >-- >marty schoffstall >schoff%rpics.csnet@csnet-relay ARPA >schoff@rpics CSNET >seismo!rpics!schoff UUCP >martin_schoffstall@TROY.NY.USA.NA.EARTH.SOL UNIVERSENET > >RPI >Computer Science Department >Troy, NY 12180 >(518) 271-2654 Since I posted the last message, some more followups have come into our machine. The people reading this group include an especially high level of TCP/IP users. I wonder whether the networking terminology breaks cleanly into two or three camps one of which is the ARPA usage. I am sure that my usage does not reflect just Ungermann-Bass's terminology but those of some other 'significant portions of the free world.' I'm curious as to what other sets of terminology are widely used. My intent is not to say that I'm right or you're right or engage in any battles. Incidentally, I posted an article earlier today with a full set of definitions the way I use them. My LAN books with definitions from other people are at home. If it seems worth-while (if I need them to defend my terminology :-) I'll post some things from there. -- Skip Addison {lll-crg, decwrl, ihnp4}!amdcad!cae780!ubvax!skip
jmg@cernvax.UUCP (jmg) (02/18/86)
In article <1828@cbosgd.UUCP> mark@cbosgd.UUCP writes: >Incidently, is there a bridge between Ethernet (or 802.3) and Starlan >available or in the works? Sure might be handy for cabling to run an >Ethernet backbone trunk with Starlan into the offices, or on the other >hand, to use Starlan for the building wiring (to reuse existing wiring) >but to plug in boxes with an Ethernet interface. I'm thinking of something >inexpensive - almost like an adaptor, not a big expensive general purpose >bridge. The answer to this question would be very interesting. However, does Starlan really exist yet? Neither net.lan nor net.dcom has much, if any, mention of Starlan. What I want to know is where can I get it, and how much will it cost.