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Re: Optical bypass switches (Re: MAE-East still no generator)
by Dave Curado 08 Sep '96

08 Sep '96

> A thought I just had. How many folks have optical bypass switches on > their fddi connections? If a enough providers' equipment fail without > bypassing, the ring can get partitioned into different sections which > might explain some of this. Supposedly DRA's router is plugged into > the gigaswitch, but I don't have a gigaswitch manual to check what > happens with ring partitions. Perhaps we're getting off of the nanog topical area here, but... To the best of my knowledge, the fddi ring at mae-east is a concentrator type ring, a to m / b to m type of thing... instead of a fddi trunk type of ring with a to b and b to a. MFS may have a number of concentrators hanging off of the Gigaswitch. One of the nice things about a concentrated ring, if you will, is that individual ports can come up and down... the ring transitions, but when a node or nodes go down, the ring doesn't partition. One note of humor about optical bypasses... although I've never used them, I'm told they're less reliable than most fddi cards -- they end up breaking and causing more problems then if you lived without them. =-) davec

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Re: MAE-East still no generator
by Justin W. Newton 08 Sep '96

08 Sep '96

At 10:55 AM 9/8/96 DST, Peter Lothberg wrote: > >So, can someone explain what the problem is? > >MAE-East is a telco facility (well...) but if I look at one of our routers; > >ICM-MAE-E uptime is 2 weeks, 4 days, 14 hours, 12 minutes >System restarted by reload at 14:40:57 EDT Tue Aug 20 1996 Actually my router there is running AC and is running with 11 weeks uptime (restarted by a relaod). I don't have any peering seesions that were up for more than three days though. Me not losing power doesn't help me if there's no way to talk to anyone else. Justin Newton Internet Architect Erol's Internet Services

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Optical bypass switches (Re: MAE-East still no generator)
by Sean Donelan 08 Sep '96

08 Sep '96

>This is funny, I did loose my IBGP peers, maybe the MFS provided >IDSU is on AC power... -:) It wouldn't hurt to check. When doing a physical check of our facilities in the past, we've discovered MFS had installed some AC powered equipment on our rack. Other telco's have done the same thing. If you have an AC outlet too close to your rack, I've noticed even the telco techs don't like messing with DC power and plug things into the wall. A thought I just had. How many folks have optical bypass switches on their fddi connections? If a enough providers' equipment fail without bypassing, the ring can get partitioned into different sections which might explain some of this. Supposedly DRA's router is plugged into the gigaswitch, but I don't have a gigaswitch manual to check what happens with ring partitions. -- Sean Donelan, Data Research Associates, Inc, St. Louis, MO Affiliation given for identification not representation

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RE: MAE-East still no generator
by Jim Browning 08 Sep '96

08 Sep '96

In some telco facilities that do have AC generator backup, there are a few seconds of down time while the generator kicks in. In these spaces, AC equipment will in all likelihood re-boot, while DC equipment stays up through the transition. -- Jim

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Re: MAE-East still no generator
by Sean Donelan 08 Sep '96

08 Sep '96

>Just out of curiosity, does anyone have any personal experience with >losing utility-provided power more than, say, three times in a day? Plenty. When power goes out around here, its going to go up and down several more times. DRA is located between several organizations concerned with real money, Bridge Information handles real-time trading feeds, MasterCard International does credit cards and Western Union/AT&T does money orders. The standard operating procedure around here is three backup generators. Nothing can ruin your trading day faster than a power failure just at the moment you have your backup generator torn apart for maintenance. With 24 hour trading becoming the norm, all day is trading day. Two generators usually start immediately, with the third one held as a spare. DRA won't make the news. But if you hear MasterCard International is down, DRA will likely have suffered the same fate. P.S. a generator hint, don't forget to keep your fuel tanks warm. As several sites in the northeast found out a couple of winters ago, diesel fuel gels at very cold tempatures. -- Sean Donelan, Data Research Associates, Inc, St. Louis, MO Affiliation given for identification not representation

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Re: MAE-East still no generator
by matthew＠scruz.net 08 Sep '96

08 Sep '96

Original message <199609081405.KAA04199(a)netaxs.com> From: Avi Freedman <freedman(a)netaxs.com> Date: Sep 8, 10:05 Subject: Re: MAE-East still no generator > > > Our real problem is getting them to fit properly in 23" racks :) > > > > ===================================== > > George Hall 916-565-4500 > > While this may not apply to 7513s, we've found that super-sturdy $25 > 23" or 19" rack shelves (and Greybar sells the Chatsworth sturdy > shelves for $75 or so) take a 7507 or 7000 (or 7505/7010) *very* well, > and there's not need to bother with the rack-harnesses. > > Avi We have facilities on both sides of the San Andreas (our main offices are in one of the downtown Santa Cruz buildings that *didn't* collapse in 1989) and don't share your view of shelves :) -matthew kaufman matthew(a)scruz.net

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Re: MAE-East still no generator
by Rob Liebschutz 08 Sep '96

08 Sep '96

In the Alternative energy arena, Trace Engineering makes a 4000 and 5500 watt 48 VDC sine wave inverter that supports stacking of two inverters to double the capacity/reliability. It's probably not designed to be rackmountable though. For smaller applications, Exeltech makes physically compact solid state sine wave inverters ranging from 250 - 6000 watts. If your running AC equipment with non-switching type power supplies, like CSU/DSU's, monitors or MUXes watch out for any inverter that does not generate a true sine wave. Square waves and modified sine waves can fry such equipment. And Yes, you do need hefty wiring on DC equipment due to the voltage drop created when transmitting high current at low voltage. I have a 400 amp hour battery bank in my van with a 1200 watt inverter mounted about 10 feet away and I used 2/0 (that's pronounced 2 ought - heaver than 0 gauge) wire for a proper connection. There are formulas for calculation of the correct wire gauge. Heavy wire that is flexible enough to be routed around corners and through racks is made of braided conductors and is commonly available from welding suppliers. Trace Engineering can be reached at 206-435-8826. Exeltech can be reached at 817-595-4969. I could provide lists of vendors of such equipment if that is appropiate. Rob

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Re: MAE-East still no generator
by Vadim Antonov 08 Sep '96

08 Sep '96

Robert E. Seastrom <rs(a)bifrost.seastrom.com> wrote: > From: Andrew Partan <asp(a)partan.com> > > So what are you using? AC or DC? If you are not on DC, I would > switch. Maybe you would have better luck. >You took the words right out of my mouth. -48vDC is *so* much cleaner >and less troublesome than mains AC (or even upsed AC) that I urge all >my clients to use it for *everything* whenever it's available. Typically telco setups have about 30min-1hr of AC UPS capacity and 4-6 hrs of 48V battery capacity. Last time i was at MAE-East it didn't have any backup AC power and a nice DC setup. BTW, the cheap solution for DC hookup would be using a power inverter. --vadim

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Inverters
by mo＠uu.net 08 Sep '96

08 Sep '96

Gee, you can either do an Alta Vista search, or even ask MFS what they use to power AC things from CO-DC supplies. the one that seems most interesting is Exceltech out of Dallas. they have a modular inverter system which makes its ratings at 100% duty cycle (ie, all the time). they can rack and stack up to 20KVA per assembly, if my feeble memory serves me right. last time I looked, MFS used the smaller non-modular Exceltech units to power AC things they supplied on MAE-EAST (ie, at their end). Don't succumb to the stupid idea of buying a UPS without batteries and then connecting to the DC supply. most ups units smaller than a refrigerator have to be significantly derated to be used in "pure interver" service. the manufacturers scream when you ask them about this. of course, 28.8 modems, 10-base-T hubs, and everything else you need IS available DC powered. you just have to be diligent. (grin) but there are times when using an AC thing *is* more expedient. Just plug the cord into a real inverter running off house DC. Good luck. -Mike O'Dell UUNET Technologies

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Re: MAE-East still no generator
by Peter Lothberg 08 Sep '96

08 Sep '96

> > So, what's the fuzz here? > > > > (Don't you all use -48Vdc in telco pops?) > > > > --Peter > > The fuzz is that most people use AC supplies in their CSUs and routers. > My best guess would be that it's so that they could move those boxes > out of the telco environement (if needed) and run them on AC. You can swap the PS in any cisco box, on some models you don't even need a screw driver. As someone already pointed out, it takes half the components to do UPS -48V than UPS 110V/230V. Where I live the comercial power is more reliable than the small UPS boxes, so the lesson is, UPS'es has to come in pairs.. --Peter

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