alan@cunixc.columbia.edu (Alan Crosswell) (01/07/88)
I'm looking for suggestions on connecting two token-ring networks that are located in geographically distant buildings that can only be connected by leased T1 circuits. The token-rings are to be used for a few purposes: - Connect PS/2's running as SNA 3270's to an IBM 3090 at the main site running your basic MVS/CICS type of system. The 3090 connects to the ring via (many) 3174 control units. - Some PC LAN stuff (like Novell). - TCP/IP. (There will be gateways to various IP ethernets, etc.) In other words, the rings speak multiple network families. So, is there either a remote token-ring bridge or a multi-protocol router that supports SNA and IP? The Proteon p4200 does IP, DECNET and XNS routing, but not SNA. I have a document from U-B issued in Feb. '87 that talks about remote token-ring data link bridges but my sales rep tells me the product does not yet exist. Wellfleet docs only talk about ethernet. Can you make an RT PC shove IP and SNA down the same SDLC link (and can it handle T1)? What about putting the RT's in front of a pair of ethernet data link bridges (like the vitalink)? It's gross, but IP routing will work that way. Will SNA? Is the only solution at this point in time to have T1 muxes with remote 3174's hung off the remote token-ring to get the SNA terminal access to the 3090 and a pair of p4200's on another piece of the mux for the IP routing? A second related question has to do with connecting a large number of rings (30) to the main ring that the 3090 is on. It looks like it's possible to use fiber repeaters and have each of the 30 rings appear in the central location so that all the bridges can be centrally maintained, secured, etc. Does anybody make a ring bridge that you can plug into more than two rings? It seems kind of absurd to have a room with 30 PC's stacked on top of each other (although that's better than having them located in 30 seperate hard to reach equipment closets). Again, a multi-protocol router sounds like it would be better than a data link bridge but SNA has to be one of the things it can route. Thanks in advance for any help you can offer. Feel free to tell me that I don't know what I'm talking about (especially with respect to SNA). I don't. Alan Crosswell User Services, Center for Computing Activities Columbia University