conrad@lasspvax.UUCP (Conrad Cady) (09/11/85)
Is there an Ethernet to Ethernet dedicated packet-passing machine that
anyone know of? Do you know where it can be purchased, or the price?
Here's our situation. We want to attach ourselves to a local Ethernet,
and were allowed one connection, but we'd like to hook several workstations
and devices into it. We've decided that we'd like our own Ethernet, with a
gateway to the other one. Rather than having our 750 act as the gateway,
we'd like to explore the possibility of using some dedicated box as the
gateway.
Does anyone have any ideas? Info?
Thanks very much,
Conrad Cady and Todd Olson
--
Conrad Cady, 513 Clark Hall LASSP, Cornell U., Ithaca, NY 14853 (607)256-3963
{ihnp4,decvax,allegra,vax135}!cornell!lasspvax!conrad conrad@lasspvax.arpadick@ucsfcca.UUCP (Dick Karpinski) (09/14/85)
In article <515@lasspvax.UUCP> conrad@lasspvax.UUCP (Conrad Cady) writes: > > Is there an Ethernet to Ethernet dedicated packet-passing machine that >anyone know of? Do you know where it can be purchased, or the price? > > Here's our situation. We want to attach ourselves to a local Ethernet, >and were allowed one connection, but we'd like to hook several workstations >and devices into it. We've decided that we'd like our own Ethernet, with a >gateway to the other one. Rather than having our 750 act as the gateway, >we'd like to explore the possibility of using some dedicated box as the >gateway. > There are lots of possibilities: 1. A DEC DELNI can be used as a multi-station transciever. In fact, if there were no other (remote) machines, I think you wouldn't need any Ethernet cable at all. I believe someone else makes a similar device, perhaps TCL (415) 657-3800. 2. A repeater makes only one connection, but it must be figured in the maximum length calculations and of course all traffic is seen on both Ethernet wires. DEC and Ungermann/Bass (408) 496- 0111 and InterLan (617) 692-3900, among others, supply such. 3. A buffered repeater makes only one connection and does not affect max length calculations. All traffic is, however, still seen on both wires. I believe U/B makes one. 4. Filtered repeaters would only pass traffic intended for the other wire, but I know of none. 5. Bridges and gateways pass some or all of the traffic but also impose other constraints: a. Only one protocol (DECnet, TCP/IP, and XNS are all popular) b. Limited throughput (VitaLink's TransLan handles 224kbps max) c. Must be explicitly addressed (only the TransLan listens to all traffic, passing as appropriate, as I understand it. This is the elusive MAC (media access control?) level bridge.) d. High cost compared to repeaters, even buffered ones. Is that enough more than you wanted to know? Dick ps. PLEASE flame me if I got any of that wrong! -- Dick Karpinski Manager of Unix Services, UCSF Computer Center UUCP: ...!ucbvax!ucsfcgl!cca.ucsf!dick (415) 666-4529 (12-7) BITNET: dick@ucsfcca Compuserve: 70215,1277 Telemail: RKarpinski USPS: U-76 UCSF, San Francisco, CA 94143
sid@linus.UUCP (Sid Stuart) (09/25/85)
What you want is an ethernet bridge. We will be testing one from Applitek over the next month. They run about 13K apiece and you need two. Thats a lot of money, but they do packet filtering and can be connected with fiber or baseband or broadband cable. Applitek Corporation 107 Audubon Road Wakefield, MA 01880 617 246 4500 sid stuart