baw@sharkey.cc.umich.edu (Brian Wolfe) (07/18/89)
I have about $6000 (at most $8000) to bridge 3 standard ethernet subnets,
so far the best deal I can find is on 2 of Retix' low-end bridges that
are rated for 6000 'frames/second'... is that fast enough for joining segments
that have about 10 hosts each?? Security is something of an issue since
there is clinical data on some hosts and research data on others, so I would
like some control over access.
So far I've looked at bridges from Micom, Raycom, Retix and DEC, are there
any other vendors that I should try?
Are there any bridges that I should avoid like the plague?
I would appreciate any recommendations you may have and I will gladly
post a summary to the net!
Thanks,
Brian.
--
Brian Wolfe Internet: baw@terminator.cc.umich.edu
Systems Analyst UUCP: {rutgers,uunet}!sharkey!brian
Henry Ford Hospital Voice: (313)-876-7461
Detroit, MI 48202 FAX: (313)-875-0315eli@spdcc.COM (Steve Elias) (07/18/89)
baw@terminator.cc.umich.edu (Brian Wolfe) writes: > >I have about $6000 (at most $8000) to bridge 3 standard ethernet subnets, >so far the best deal I can find is on 2 of Retix' low-end bridges that >are rated for 6000 'frames/second'... is that fast enough for joining segments >that have about 10 hosts each?? if the bridges can maintain 6k frames/sec steady state, then they should be plenty fast. unfortunately, many bridge companies are playing bullshit specsmanship games. example: quoting "burst" performance numbers. taken to the limit, one could quote infinite performance using this technique. beware. >Security is something of an issue since >there is clinical data on some hosts and research data on others, so I would >like some control over access. i'm not sure what sorts of features Retix offers in this dept. -- ...... Steve Elias (eli@spdcc.com);(6178591389);(6178906844) {} /* so much entropy, so little time */
battan@qtc.UUCP (Jim Battan) (07/18/89)
Cabletron just came out with two bridges that are about half the size of DEC's, one at $3,000 and one at $5,500. The first one forwards 8Kpps, the second 10Kpps, either of which should be adequate for a network your size. If they're like other Cabletron equipment, I would expect them to be of high quality. -- Jim Battan Quantitative Technology Corportation (QTC), Beaverton, OR +1 503 626 3081 ...!tektronix!sequent!qtc!battan
kwe@bu-cs.BU.EDU (kwe@bu-it.bu.edu (Kent W. England)) (07/18/89)
In article <3769@ursa-major.SPDCC.COM> eli@ursa-major.spdcc.COM > (Steve Elias) writes: >>I have about $6000 (at most $8000) to bridge 3 standard ethernet subnets, >>so far the best deal I can find is on 2 of Retix' low-end bridges that >>are rated for 6000 'frames/second'... is that fast enough for joining segments >>that have about 10 hosts each?? > > if the bridges can maintain 6k frames/sec steady state, then > they should be plenty fast. unfortunately, many bridge companies > are playing bullshit specsmanship games. example: quoting > "burst" performance numbers. taken to the limit, one could quote > infinite performance using this technique. beware. > Keep in mind the difference between filtering and forwarding rates. A bridge has to be able to scan each and every frame that flies by. This is the filtering rate. It should be greater than your expected Ethernet segment traffic. Make sure you understand whether it is total or per interface. You might have to take the quoted performance and divide by two. The forwarding rate is how fast it can move frames that need to be sent to the "other side". Burst rate is important, as for example, in a network file system access, where a server might blast several frames constituting some large chunk of data at the bridge back to back (or nearly so). Steady state throughput is another important measure of how much offnet traffic from all sources can be forwarded. Then you need to know whether you need or care about spanning tree, learning, broadcast forwarding control and extra filtering for access and security. Steve is right about the specsmanship. This is unfortunately something we have to put up with until we can decide just what we mean by bridge and router performance and how it is we measure traffic on a net.
henry@utzoo.uucp (Henry Spencer) (07/19/89)
In article <3769@ursa-major.SPDCC.COM> eli@ursa-major.spdcc.COM (Steve Elias) writes: > if the bridges can maintain 6k frames/sec steady state, then > they should be plenty fast. unfortunately, many bridge companies > are playing bullshit specsmanship games. example: quoting > "burst" performance numbers... Another sharp bit of specsmanship which is (I'm told) not uncommon is to quote "I/Oput" numbers as "throughput", i.e. "6000/s" might really be 3000/s in plus 3000/s out. -- $10 million equals 18 PM | Henry Spencer at U of Toronto Zoology (Pentagon-Minutes). -Tom Neff | uunet!attcan!utzoo!henry henry@zoo.toronto.edu