morgan@navajo (Bob Morgan) (10/23/87)
In the wake of the IP-over-802 draft RFC, I'd like to ask a few questions: 1. Is any network anywhere using 802.2 over 802.3? Does anyone running a large Inter-Ethernet have any plans to move to 802.2 over 802.3? 2. Is there any published justification for the use of source routing in IBM's bridging of token-rings, given its apparent violation of the network/logical-link/MAC layering principles? Can anyone anywhere defend it? 3. Is anyone anywhere doing MAC-level interconnection of token-ring and Ethernet/802.3 networks? 4. Has the 802.1 committee published anything about what it is up to? 5. Is SNAP an official part of 802.2? Is there anything written down about it anywhere? It's not in my copy of 802.2. I've got lots more, but those will do for now. In wonderment, - RL "Bob" Morgan Networking Systems Stanford University morgan@jessica.stanford.edu
melohn@SUN.COM (Bill Melohn) (10/25/87)
>1. Is any network anywhere using 802.2 over 802.3? Does anyone >running a large Inter-Ethernet have any plans to move to 802.2 over >802.3? You can run TCP/IP using SNAP encapsulation over both 802.3 and 802.4 using the Sunlink OSI software. Even though the 802.3 and Ethernet networks share the same hardware interface, they have to be separate IP networks using the Sun as a gateway. This is of limited utility between hosts that understand Ethernet today; however in the future it is possible that such a gateway capability will be necessary for talking between implementations which only do Ethernet and those who only do 802.2/802.3, or 802.2 LLC bridges between different 802.X media.
hedrick@TOPAZ.RUTGERS.EDU (Charles Hedrick) (10/26/87)
Let me point out to any vendors who may be on this list that any vendor who produces a TCP/IP implementation for Ethernet that understands only the SNAP encapsulation is going to have a lot of irate customers. We expect TCP/IP implemenations for Ethernet hardware to interoperate with existing implementations. If they want to do something else as well, that's fine with me. But if it won't talk to 4.3, we will consider that it is not TCP/IP.
skip@ubvax.UB.Com (Stayton D Addison Jr) (10/28/87)
In article <12030@labrea.STANFORD.EDU> morgan@jessica.stanford.edu (RL "Bob" Morgan) writes: >In the wake of the IP-over-802 draft RFC, I'd like to ask a few >questions: > >1. Is any network anywhere using 802.2 over 802.3? Does anyone >running a large Inter-Ethernet have any plans to move to 802.2 over >802.3? > UB's Token Ring - Ethernet Data Link Bridge puts the 802.5 packets on the 802.3 network, 802.2 LLC headers and all. My incomplete understanding is that HP's TCP/IP implementation uses 802.3, not Ethernet. I don't know whether they use the 802.2 LLC headers. >2. Is there any published justification for the use of source routing >in IBM's bridging of token-rings, given its apparent violation of the >network/logical-link/MAC layering principles? Can anyone anywhere >defend it? > Without endorsing the concept, I can repeat what I understand to be the primary argument. For security or other considerations (error rates, etc), a node may want to direct the flow of its packets thru the internetwork to avoid certain routes/links. In practice, I doubt many nodes have or will ever do this. >3. Is anyone anywhere doing MAC-level interconnection of token-ring >and Ethernet/802.3 networks? > Yes. Ungermann-Bass has announced an 802.3-802.5 Data Link Bridge. It doesn't do anything with Ethernet frames, however; just 802.3 (unless the frames are from Ungermann-Bass equipment). The problem is mainly the ETYPE field which can not be derived from anything in the 802.5 header. >4. Has the 802.1 committee published anything about what it is up to? > I don't attend the meetings, but I understand that rev B of the 802.1 internetworking draft standard was published in March. It was to be voted on about now, I think. >5. Is SNAP an official part of 802.2? Is there anything written down >about it anywhere? It's not in my copy of 802.2. > Don't know. >I've got lots more, but those will do for now. > >In wonderment, > >- RL "Bob" Morgan > Networking Systems > Stanford University > morgan@jessica.stanford.edu -- Skip Addison {lll-crg, decwrl, ihnp4}!amdcad!cae780!ubvax!skip or sun!amd!ubvax!skip