RE: BBN (GTE) Suffers another major power problem.
-----Original Message----- From: Jonah Yokubaitis [SMTP:barron@texas.net] Sent: Friday, August 08, 1997 2:08 PM To: Nathan Stratton Cc: Matthew White; nanog@merit.edu Subject: Re: BBN (GTE) Suffers another major power problem.
Incorrect. Stop using AC equipment in your pops. Use DC equipment and get a _good_ DC Powerplant. Every carrier Class4/5 switchroom usually has 10-20,0000 AMP/hours of standby power. 1 DSC or Nortel switch sucks _quite_ a bit more power than even the largest of superpops. Every carrier has _at least_ 4hours of battery plant (most have 8-12). Relying on generators is a _bad_ idea.
Its not hard to have 4-12hours of standby battery plant.
Lucent/Lorain/Peco2 all make rather nice rectifiers, and C&D/Lucent/GDB all make some nice vented batteries. By going DC you also don't get hit with the inefficiencies of AC --> DC --> AC --> DC.
You can bet that MCI/Sprint don't have a piece of AC equipment in their facilities and most likely are laughing their asses off right now.
Not quite as simple Jonah.... CO equipment is designed for 48v for many reasons. It's also designed to deal with concrete floors, inefficient HVAC, dust, etc. Unfortunately, a modern megapop consists of a lot of interesting equipment that doesn't come in 48v DC versions. Alpha 8400s, Large SGIs, and server like things (yeah, I know, there are companies who make retrofit kits for some of them, but they're not standard). The real issue is planning... MAE E and MAE W *weren't* designed for the things that MFS is stuffing in them. Most of the other pops have the same problem. It *is* possible to design a facility that is run off an inverter permanently, which is connected to a UPS, which is connected to utility power, and to a diesel generator, which *is* able to cope with extended failures of _utility power_ without affecting the equipment (routers, switches, modems, and servers) at all. And I think the modern facilities will be built that way. 4-12 hours of batteries is serious when you're talking about a large hosting facility. Sprint/MCI may be laughing, but they're haveing to scramble to build POPs capable of supporting server farms because they can't do that now. And another thing, batteries or not, *no-one* can easily survive a catastrophic event like a fire, an explosion, or even the wires that got eaten in BBNs Stanford center last year. (Didn't AT&T hose most of Chicago's loop area a few years ago, for more than a *week*?) I bet they had DC in their vault. Didn't help them much... Rodney Joffe Genuity Inc., a Bechtel company http://www.genuity.net
On Fri, 8 Aug 1997, Rodney Joffe wrote:
It's also designed to deal with concrete floors, inefficient HVAC, dust, etc.
This is interesting, as we have two colo sites now... One fits the description above (somewhat), and one fits the description below...
It *is* possible to design a facility that is run off an inverter permanently, which is connected to a UPS, which is connected to utility power, and to a diesel generator, which *is* able to cope with extended failures of _utility power_ without affecting the equipment (routers, switches, modems, and servers) at all. And I think the modern
The site where we locate our dialup equipment (ACC-Old Slip) is old-school telco. All 48V, all battery backed-up if you take the DC feed. It's brand new, but it does not have a raised floor, just overhead channels for all the telco wiring... They thought we were crazy when we asked for AC, but when told how many amps a USR TCH draws, they happily brought more AC to us. We're backed up by a generator, but that's it. During the time it takes to crank it up, we're dead. Now at Telehouse NY, (our cabinet being right across from Genuity, btw) they tell us that all power is coming from an inverter, and there is enough battery power to keep the entire facility going until the generator comes online. They even invite you to come out and see them disconnect the utility co. power during their quarterly tests... This is primarily a "datacenter" with a much higher count of things that say "Cisco" on them than those that say "Lucent" or "AT&T". They also claim they have 3 days of diesel fuel available... So I guess the rule here is, put your 48V stuff at a telco colo, and put the big AC stuff at a modern datacenter... Charles ~~~~~~~~~ ~~~~~~~~~~~ Charles Sprickman Internet Channel INCH System Administration Team (212)243-5200 spork@inch.com access@inch.com
On Fri, 8 Aug 1997, Charles Sprickman wrote: | |Now at Telehouse NY, (our cabinet being right across from Genuity, btw) |they tell us that all power is coming from an inverter, and there is |enough battery power to keep the entire facility going until the generator |comes online. They even invite you to come out and see them |disconnect the utility co. power during their quarterly tests... This is |primarily a "datacenter" with a much higher count of things that say |"Cisco" on them than those that say "Lucent" or "AT&T". They also claim |they have 3 days of diesel fuel available... How long does it take your generator to kick in? IMO you had _better_ have 4hours of battery plant *MINIMUM* in case your generator does not start. The 4hours is needed so you can get your rollup generator (from a generator contractor) drive to your pop and hooked into your external power tap. We have a 225KW Onan that goes from off to fully operational in 5seconds. Its tested (non-loaded) every monday, and tested with full load every 4th monday. I have seen a _lot_ of generator problems. |So I guess the rule here is, put your 48V stuff at a telco colo, and put |the big AC stuff at a modern datacenter... huh? Every modern datacenter I have seen is running -48VDC. Are you aware of how much electrical interference AC power causes? Your equipment _all_ runs on DC power. The AC power supplies in your equipment is just rectifying the power from AC --> DC (usually 5v or 12v DC). By running AC power backup systems, you are losing ~20-30% effiency due to power conversions. Jonah
On Fri, 8 Aug 1997, Rodney Joffe wrote: |> Incorrect. Stop using AC equipment in your pops. Use DC equipment and |> get a _good_ DC Powerplant. Every carrier Class4/5 switchroom usually |> has 10-20,0000 AMP/hours of standby power. 1 DSC or Nortel switch |> sucks _quite_ a bit more power than even the largest of superpops. |> Every carrier has _at least_ 4hours of battery plant (most have 8-12). |> Relying on generators is a _bad_ idea. |> |> Its not hard to have 4-12hours of standby battery plant. |> |> Lucent/Lorain/Peco2 all make rather nice rectifiers, and |> C&D/Lucent/GDB all make some nice vented batteries. By going DC you |> also don't get hit with the inefficiencies of AC --> DC --> AC --> DC. |> |> You can bet that MCI/Sprint don't have a piece of AC equipment in |> their facilities and most likely are laughing their asses off right |> now. |> |Not quite as simple Jonah.... CO equipment is designed for 48v for many |reasons. It's also designed to deal with concrete floors, inefficient |HVAC, dust, etc. | |Unfortunately, a modern megapop consists of a lot of interesting |equipment that doesn't come in 48v DC versions. Alpha 8400s, Large SGIs, |and server like things (yeah, I know, there are companies who make |retrofit kits for some of them, but they're not standard). Use invertors off your -48VDC plant for your AC equipment. An AC UPS: AC feed from electric co --> rectifier --> DC batteries --> inverters I have yet to see an AC UPS with a longer runtime than 2hours (100KW+) with full battery options installed. Exide/Liebert make excellent UPS systems, but they are _not_ meant for extended runtime. Instead they are meant for a graceful shutdown of all systems when extended power outages occur. Jonah
participants (3)
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Charles Sprickman -
Jonah Yokubaitis -
Rodney Joffe