davew@gvgpsa.UUCP (David C. White) (11/07/87)
Has anyone had any good/bad experiences with the Cabletron Systems MR-9000C Multiport Repeater for thin wire ethernet? Does it exactly duplicate DEC's DEMPR in fuctionality? The costs (after our discount with DEC) are very close, so I am looking for information that might make me want to look at the MR-9000C. I will summarize to the net if there are enough responses. Thanks in advance. -- =================================================================== Dave White Grass Valley Group, Inc. P.O. Box 1114 Grass Valley, CA 95945 UUCP: ...!tektronix!gvgpsa!davew PHONE: +1 916 478 3052
ron@topaz.rutgers.edu (Ron Natalie) (11/11/87)
Gee, last I checked the MR-9000C (at least with our discounts) was substantially cheaper that the DEMPR. We used one for a while without any trouble we could directly attribute to it (we had one strange problem, one day, but it probably was something else). The Cabletron unit does have some nice blinking lights on it. -Ron
davew@gvgpsa.UUCP (David C. White) (11/17/87)
In article <651@gvgpsa.UUCP> I wrote: >Has anyone had any good/bad experiences with the Cabletron Systems >MR-9000C Multiport Repeater for thin wire ethernet? Does it exactly >duplicate DEC's DEMPR in fuctionality? The costs (after our discount >with DEC) are very close, so I am looking for information that might >make me want to look at the MR-9000C. I will summarize to the net if >there are enough responses. Since I have had several requests for the information I received on this subject I thought it best to post the responses to the net. Thanks to those who took the time to respond. ################ From: ucdavis!ucbvax!uwvax!bu-it.bu.edu!ll-xn!ccjap Organization: Boston Univ. CS Dept. Boston University was involved with Cabletron in getting the MR-9000 built and as such have had a long and happy relationship with the company. We served as one of (if not the original) MR 9000 beta sites. Roughly, we have had an MR9000 in operation non-stop for over a year. Cabletron appears to have come up with a well behaved unit that has several benefits over the DEMPR. Mainly, it has the "LANView" LEDs to indicate Tx, RX, etc. on each segment. It is smaller than the DEMPR and has a little bracket that appears to be a guard against accidental unplugging of the coaxs at the unit or it is a strain relief (we don't use it and the manual doesn't mention it. As far as I know, it may be some modern kitchen aid). On the down side, the unit has a little DC boxer fan that is quite loud. It also appears that there aren't any rack mount kits (not that DEC does :). I cannot say that it faithfully duplicates the DEMPR because we haven't had the opportunity to perform exhaustive tests on both units in equal environments. In addition, the DEMPR that we do have is one which contained "THE" bug/flawed IC, resulting in the need to install a LAN-Bridge 100 between the DEMPR and the Thick Ethernet. What I can say is that we have a cluster of about 20 diskless SUN clients (3/50s, 2/160s), a 3/180 server and a 3/280 server, all on the same Ethernet. Most of the diskless units use Thin Ethernet segments which terminate at the MR9000. We have been very happy with the performance and have found no problems on our ethernet directly attributable to the MR9000. It performs quite well in isolating faulty segments and has an LED indicator for each segment to show which segments are faulty. We have never had to replace the unit or have it repaired. I certainly wouldn't promise you that the MR9000 is a flawless beast but we are satisfied with the units to the point that we are installing them where ever Thin Ethernet is needed. Our fondness for the MR9000 is not only based on price but on the fact that we are a relatively small group of engineers and technicians that design, install, and manage virtually every LAN on the campus. Having a reliable product that provides the necessary tools/information to help debug a broken net is essential to our operations. ########################## From: ucdavis!ucbvax!ucla-cs!rutgers!gatech!codas!novavax!utx1!hilmes (Douglas Hilmes) We bought a MR-9000C for our thin-wire connections. So far it has worked fine, but we've only had it for a month. The price was close to the DEMPR, but Cabletron was able to give us faster delivery than what we would get from DEC. We also went to other vendors for cable, T-connectors and the like, I believe the cost per port (232 ports ) came out to somewhere around $15 each. Hope this helps. ############## From: ucdavis!ucbvax!uwvax!harvard!cfa!wyatt (Bill Wyatt) We have one and are happy with it. It works as advertised. We have no DEMPR's, so I guess I can't swear it duplicates it, but I think it's actually better, since it gives activity lights (xmit, recv, collision) for each of the segments. ################## From: Walter Underwood <tektronix!cae780.TEK.COM!hplabs!hpcea!wunder> Well, I don't have any experience with Cabletron, but inside HP, we use the HP ThinLAN hub all over the place. One AUI/Transceiver port, and four BNC's, for a five-way repeater. As I understand it, the DEC version has an internal terminator, so you *must* put it at one end of a ThinLAN. The HP box meets the specs for a normal tap, so you've got a lot more flexibility in wiring. You can put the hub any place on the cable. We like to run one ThinLAN around each set of cubicles (usually a U-shape), and hang that off a ThinLAN hub. When people switch over to diskless, we can replace the repeater with a filtering bridge. Running the cables along natural workgroup boundaries makes the switchover work, since each cable tends to be a local traffic group. I think the HP ThinLAN hub is a 28645A. ################## From: ucdavis!ucbvax!tc.fluke.COM!jeff (Jeff Stearns) We have only begun to use the Cabletron MR-9000C; it works fine so far. I'm unable to comment on its compatability with the DEC product. We have greater experience with other Cabletron products, and they have earned our highest respect. Of the set {Interlan, DEC, Sun, 3COM, BICC, Cabletron}, the clear winner on our Ethernet is Cabletron. If Cabletron makes it, buy it. ################### From: ucdavis!ucbvax!tc.fluke.COM!norm (Norm Seethoff) We have one MR9000 in use now, a second on order, and plans to add another half dozen during the next 6 months. The one we have installed just sits there and works. It has been in use for about 3 months now. Some of the Cabletron "features" we prefer over the DEMPR are: cleaner rack mounting (cables exit on rear of unit) status annunciators for each cable segment lower list price We tend to put multiport repeaters behind transceiver multiplexers. To my great surprise, DEC recommends derating the maximum coax length used on your "backbone" from 500M to 300M if you take this approach (see pages 4-3 and 4-4 of the DECconnect System Planning and Configuration Guide). This little restriction maked the DEMPR unattractive for our application. Cabletron places no such restriction upon their multiport repeater. We use Cabletron transceivers, transceiver multiplexers, multiport repeaters, transceiver testers, and transceiver cables in a very heterogeneous computer environment. We have been pleased with the performance of all of the Cabletron products. I wish I could speak as positively about some of the other transceiver and cable products we have used in the past. -- =================================================================== Dave White Grass Valley Group, Inc. P.O. Box 1114 Grass Valley, CA 95945 UUCP: ...!tektronix!gvgpsa!davew PHONE: +1 916 478 3052