Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site bu-cs.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!whuxlm!harpo!decvax!genrad!panda!talcott!harvard!bu-cs!root From: root@bu-cs.UUCP (Barry Shein) Newsgroups: net.lan,net.dcom Subject: Re: ETHERNET on Broadband Message-ID: <454@bu-cs.UUCP> Date: Mon, 1-Jul-85 20:21:47 EDT Article-I.D.: bu-cs.454 Posted: Mon Jul 1 20:21:47 1985 Date-Received: Fri, 5-Jul-85 04:01:07 EDT References: <2926@decwrl.UUCP> <449@bu-cs.UUCP>, <1263@opus.UUCP> Organization: Boston Univ Comp. Sci. Lines: 49 Xref: watmath net.lan:899 net.dcom:1077 Re: DR11-W--U/B NIU-150 --Broadband (Ungermann/Bass Broadband driver for 4.2,VMS at Boston University.) Just to clarify (a comment made by a poster indicated some confusion): The reason I entered this into the discussion was because our broadband interfaces *do* act as ethernet/broadband bridges, exactly like you would hope. We have two 4.2 vaxes with both an ethernet (DEUNA) and U/B Broadband interface which act as transparent gateways for other non-broadband hosts, for example: Eng Vax IBM3081 C.S. Student Vax C.S. Research Vax DEC2060 broadband | street | ethernet ethernet only ethernet+broadband ethernet only only only Every system in the picture can TELNET, FTP, SMTP etc to every other system in the picture as if they were on one ethernet (although because they form logically distinct subnets broadcasts have to be forwarded, like two ethernets.) I hope this clarifies something. No, does not require a DEC system, we are soon to move it to a SUN, any 4.2bsd system with sources and a DR11-W or DR11-B compatible interface would do (MultiBus,VMEbus DR11-W emulators exist.) You only need one such system per ethernet anyhow which acts as a gate. It only takes one channel on the broadband which is important to us. We will look into other interfaces such as RS232 and V.35 also to lessen the DR11-W constraint (U/B would probably have some ideas, they make several interfaces.) Yes, I would like a black box that just snapped onto an ethernet cable and broadband tap and magically forwarded to another, remote box with the same connections, but I don't like the idea of 2 or 3 dedicated channels to do it. I also wonder exactly what gets forwarded (every packet? the DEC box certainly doesn't read IP packets.) I guess for now I am using a couple of Vaxes as this 'black box'. I could imagine buying a cheap 68K 4.2 box, adding a parallel and ethernet interface and configuring in the driver and our campus' routing tables and thus acheiving this, tho probably a little expensive (well, a bit less than $10,000 for sure.) And hell, a few people could log into it also, or it could be expanded to be a print server or some such. (note that we have yet to see a performance problem, packets get forwarded thru 4.2 very cheaply.) Nah, we looked at the DEC broadband box as we were writing our own. Unless you are locked into DecNet we didn't think it was a very good solution at all, tho I will admit the choices are limited. -Barry Shein, Boston University