NAPs - Temperature vs Packet loss
We've noticed an interesting phenomenon with MAE-East. Packet loss corelates nicely to temperature. At first I assumed the relationship was Busy Network => Hot routers and also Busy Network => Packet Loss. But this is not the case. It appears to be Hot Routers => Packet Loss. Boone Boulevard MAE-East is currently running very hot. Intake temp on our router has been up to 40 degrees today, and output at 70. Under these conditions, the router (a 7010) starts dropping a pile of packets occassionally. Mostly these seem to be through the AIP and a clear int a0/0 fixes it. The time it stays fixed for is heavilly corelated with temperature. The higher the temperature, the shorter it stays fixed for. Eventually MFS put a fan on the router and it seems a lot better now, intake temperature being down to 36/37 degrees. 40 degrees is Cisco's default "warning" threshold. One would have thought boxes should work OK at 40 degrees. On the other hand one might also have thought a 18-22 degree aircon environment was a prerequisite of running a decent IXP. Is anyone else seeing high temperature and otherwise inexplicable packet loss at MAE-East? Or does anyone else have data to corelate? Alex Bligh Xara Networks
X-Mailer: exmh version 2.0alpha 12/3/96 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Fri, 28 Mar 1997 20:26:57 +0000 From: "Alex.Bligh" <amb@xara.net> Sender: owner-nanog@merit.edu Content-Length: 1220
We've noticed an interesting phenomenon with MAE-East. Packet loss corelates nicely to temperature.
At first I assumed the relationship was Busy Network => Hot routers and also Busy Network => Packet Loss. But this is not the case. It appears to be Hot Routers => Packet Loss.
Boone Boulevard MAE-East is currently running very hot. Intake temp on our router has been up to 40 degrees today, and output at 70. Under these conditions, the router (a 7010) starts dropping a pile of packets occassionally. Mostly these seem to be through the AIP and a clear int a0/0 fixes it. The time it stays fixed for is heavilly corelated with temperature. The higher the temperature, the shorter it stays fixed for. Eventually MFS put a fan on the router and it seems a lot better now, intake temperature being down to 36/37 degrees.
First I've heard of it, but sounds like you've captured a lot of empirical evidence, so could you send me your data (hopefully telling me whether these were output drops, input ignores, input drops, or other errors). Did you notice any errors logged? Anyways, send me all your usual "show ver", "show int", "show contr cbus" info (nanog un-cc'ed, please) and I'll pass it around. /Darren PS - I've noticed that ever since I moved to San Diego, people around here have been dropping like flies. Coincidence, or cause&effect? ;-)
40 degrees is Cisco's default "warning" threshold. One would have thought boxes should work OK at 40 degrees. On the other hand one might also have thought a 18-22 degree aircon environment was a prerequisite of running a decent IXP.
Is anyone else seeing high temperature and otherwise inexplicable packet loss at MAE-East? Or does anyone else have data to corelate?
Alex Bligh Xara Networks
On Fri, 28 Mar 1997, Darren Kerr wrote:
Boone Boulevard MAE-East is currently running very hot. Intake temp on our router has been up to 40 degrees today, and output at 70.
70 degrees!!! This is pushing the limit for reliable operation of electronic equipment. I know I have frequently solved problems with all sorts of equipment (computers, modems, terminal servers, routers) by dropping the ambient room temperature to below the level where it is comfortable for people to work, i.e. around 15 degrees. or by adding fans internally or externally. I think that ambient temperatures at the tops of the racks and at the room's outflow vents should be specified in IXP agreements along with a protocol for dealing with this kind of problem. And most especially, this needs to be properly engineered from the start. Michael Dillon - Internet & ISP Consulting Memra Software Inc. - Fax: +1-250-546-3049 http://www.memra.com - E-mail: michael@memra.com
On Fri, 28 Mar 1997, Michael Dillon wrote:
electronic equipment. I know I have frequently solved problems with all sorts of equipment (computers, modems, terminal servers, routers) by dropping the ambient room temperature to below the level where it is comfortable for people to work, i.e. around 15 degrees. or by adding fans internally or externally.
We had a problem with this at the Atlanta-NAP, people were complaining that it was to cold. When we warmed it up a bit, we started having problems. So now we just tell them to dress warmly. :-) Nathan Stratton President, NetRail,Inc. ------------------------------------------------------------------------ Phone (888)NetRail NetRail, Inc. Fax (404)522-1939 230 Peachtree Suite 500 WWW http://www.netrail.net/ Atlanta, GA 30303 ------------------------------------------------------------------------ "Therefore do not worry about tomorrow, for tomorrow will worry about itself. Each day has enough trouble of its own." Matthew 6:34
I experienced an airflow problem on a 7010 once which just made it shut down and restart when it got hot. Are you sure that this is not happening occesionally? It would seem to me that a 7xxx router should be able to survive its shutdown threshold without affecting performance. Brian Horvitz WebSecure, Inc. On Fri, 28 Mar 1997, Alex.Bligh wrote:
We've noticed an interesting phenomenon with MAE-East. Packet loss corelates nicely to temperature.
At first I assumed the relationship was Busy Network => Hot routers and also Busy Network => Packet Loss. But this is not the case. It appears to be Hot Routers => Packet Loss.
Boone Boulevard MAE-East is currently running very hot. Intake temp on our router has been up to 40 degrees today, and output at 70. Under these conditions, the router (a 7010) starts dropping a pile of packets occassionally. Mostly these seem to be through the AIP and a clear int a0/0 fixes it. The time it stays fixed for is heavilly corelated with temperature. The higher the temperature, the shorter it stays fixed for. Eventually MFS put a fan on the router and it seems a lot better now, intake temperature being down to 36/37 degrees.
40 degrees is Cisco's default "warning" threshold. One would have thought boxes should work OK at 40 degrees. On the other hand one might also have thought a 18-22 degree aircon environment was a prerequisite of running a decent IXP.
Is anyone else seeing high temperature and otherwise inexplicable packet loss at MAE-East? Or does anyone else have data to corelate?
Alex Bligh Xara Networks
participants (5)
-
Alex.Bligh -
Brian Horvitz -
Darren Kerr -
Michael Dillon -
Nathan Stratton