Re: [asterisk-users] Quiet 24 port POE gig switch
The per-port regulators would be non-isolated. Probably feeding off an internal 48V bus. Yes, so that will be 90 to 95% efficient, but it is fed from an isolated supply that at best will be 90%, probably less. Those numbers must be multiplied, giving 81 to 86% overall efficiency--and I am assuming best in class, which only a switch at a high price point would offer. Well, the bulb has a peak permissible operation temperature of about 160 degrees C ... so likely no extra cooling required True in open air. However, inside a metal enclosure as I described to make it applicable to the situation, the enclosure would probably get warm enough to be a fire hazard. The light bulb might still be fine after the building burned down! :-) I've designed products and put them through UL, CSA and CE safety testing. It'd still be a 400W PSU if it supplies 400W You can play various games with the numbers, such as choosing input versus output power to write in the spec. The label will have to indicate 500 W of power consumed, by law. No matter how one plays with the numbers, an 80% efficient supply that delivers 360 watts will consume 450 W, and turn 90 W into heat. If it is rated for 400 W output, it is probably in a portion of its range at 360 W where it is achieving near optimal efficiency and the above math would apply. In cases where half the loads drew less power and/or were not POE loads, the consumption would go down, and so would the heat. However the manufacturer can't design for that case and if they don't provide automatic fan control (which apparently most switches don't have), the fan must be designed for worst case, which in the above example is 100 W of heat. Also, at 25 to 50 % load, the efficiency will probably be lower because it was optimized for a larger load, and because some losses are fixed (not load dependent). This whole thread is getting stupid If some increase in understanding occurs, then it isn't a waste. No it won't change the behavior of any switches, but it might help people understand why. Wilton ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
On Mon, 2 Feb 2009, Steve Underwood wrote: Bernd Felsche wrote: Ian Cowley i...@moffat.co.uk wrote: Beware PoE switches that can't handle Class 3 (15W) on all ports. Most have fans because 24 (or 48) x 15W is hot! That's the power supplied .. which'd be at the far end of the wire. The efficiency of the PSU plays a big part in the heat dissipation. The push to compact dimensions doesn't help ... a 400W or thereabouts PSU with 24 independent outputs in 1U height? I suppose if the switch were quite deep it could be workable and quiet. The problem isn't simply of being fanless. But being quiet. Preferably below 32 dBA at 1 metres for most offices. You can do that by using fans other than the tiny, whiney, 40mm fans that vibrate at 6000 to 18,000 Hz. A couple of 80 or 120 mm muffin fans at the back or front, pushing air in (hence the deep dimensions), but the top and bottom would need recesses to allow sufficient airflow when the positions above and below are filled. So, size does matter after all. :-) 24 x 15W = 360W. Its not that big a supply really, and spread across a 1U case its not that dense a supply. A 360W desktop PC supply can be pretty quiet, so its sad none of the 1U chassis supplies are. Probably if they used a large impeller fan they could get the noise down. I guess they assume these things will be in cupboards or data centres where nobody cares. This is a poor assumption. I think you might be missing what Bernd Felsche wrote - 24 * 15W is indeed 360W, but the power supply will not be dissipating that - the phones at the far-end will. A modern switched mode PSU ought to be more than 90% efficient, so that means the PSU should only be dissipating 30 watts or so. Easy enough to keep cool with little or no fans. Same for those PC PSUs - the PSUs themselves really shouldn't be dissipating that much power (as heat). I suspect some early PSU makers just put fans in because. Early ethernet switches did get hot - because of all the switching going on in their chips, so it wouldn't surprise me if most of the heat coming out of them was actuall the Ethernet part of it - esepcially at Gb levels than the power convertors... Gordon ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
A modern switched mode PSU ought to be more than 90% efficient, In theory, yes, in practice, not likely. It is harder to get high efficiency from an isolated supply than a non-isolated one. I get ads from IC manufacturers all the time about there 90 to 95% efficient solutions, but these are boost or buck regulators--non-isolated. State of the art in commercial practice for isolated supplies is around 80 to 85%, and typical commercial practice is more like 70 to 80%. Now you have more like 60 watts of heat radiating from this power supply. Go stick a 60 watt light bulb (incandescent) in a small metal box and see how easy it is to keep cool. Wilton ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
[snipped] You can do that by using fans other than the tiny, whiney, 40mm fans that vibrate at 6000 to 18,000 Hz. A couple of 80 or 120 mm muffin fans at the back or front, pushing air in (hence the deep dimensions), but the top and bottom would need recesses to allow sufficient airflow when the positions above and below are filled. How are you getting these 80 or 120mm fans in a 1U chassis? Remember you got barely 45mm to play with at the back and front of the switch. How are you going to mount a 80mm or 120mm fan on there? Are you assuming that the units mounted above (or below) your switch is a short 1U? You can't assume that... begin:vcard fn:Singer Wang n:Wang;Singer org:The Pythian Group;Team 13 adr:116 Albert Street;;Suite 1000;Ottawa;Ontario;K1P 5G3;Canada email;internet:w...@pythian.com title:System and Database Administrator tel;work:(613) 565-8696 x298 tel;fax:(613) 565-8710 x-mozilla-html:TRUE url:http://www.pythian.com version:2.1 end:vcard ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
Singer XJ Wang wrote: [snipped] You can do that by using fans other than the tiny, whiney, 40mm fans that vibrate at 6000 to 18,000 Hz. A couple of 80 or 120 mm muffin fans at the back or front, pushing air in (hence the deep dimensions), but the top and bottom would need recesses to allow sufficient airflow when the positions above and below are filled. How are you getting these 80 or 120mm fans in a 1U chassis? Remember you got barely 45mm to play with at the back and front of the switch. How are you going to mount a 80mm or 120mm fan on there? Are you assuming that the units mounted above (or below) your switch is a short 1U? You can't assume that... A number of 1U products use large impeller fans. They take more internal space in the chassis, but they are slower and quieter. Tiny whiny seems to be the current fashion, though. Steve ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
A number of 1U products use large impeller fans I've got a CPU in a 1U package with an impeller fan. It sounds like a jet taking off! Its not quiet. Wilton ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
We got a few of those in 1U chassis.. if you think those are quiet... Steve Underwood wrote: Singer XJ Wang wrote: [snipped] You can do that by using fans other than the tiny, whiney, 40mm fans that vibrate at 6000 to 18,000 Hz. A couple of 80 or 120 mm muffin fans at the back or front, pushing air in (hence the deep dimensions), but the top and bottom would need recesses to allow sufficient airflow when the positions above and below are filled. How are you getting these 80 or 120mm fans in a 1U chassis? Remember you got barely 45mm to play with at the back and front of the switch. How are you going to mount a 80mm or 120mm fan on there? Are you assuming that the units mounted above (or below) your switch is a short 1U? You can't assume that... A number of 1U products use large impeller fans. They take more internal space in the chassis, but they are slower and quieter. Tiny whiny seems to be the current fashion, though. Steve begin:vcard fn:Singer Wang n:Wang;Singer org:The Pythian Group;Team 13 adr:116 Albert Street;;Suite 1000;Ottawa;Ontario;K1P 5G3;Canada email;internet:w...@pythian.com title:System and Database Administrator tel;work:(613) 565-8696 x298 tel;fax:(613) 565-8710 x-mozilla-html:TRUE url:http://www.pythian.com version:2.1 end:vcard ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
Paul Hales pdha...@optusnet.com.au writes: My memory of a HP procurve (a 2626 PWR from memory) was that it was quite noisy - have they changed? The 2626 is either extremely noisy or fairly noisy, depending on which you happen to get. Luck of the draw; I haven't found a way to predict it. The 2650 is almost always in the fairly category. However, the 2610-24 is fanless, which sounds great. Except the PoE versions aren't fanless. The 2610-24/12PWR is not THAT bad unless it gets hot, the 24PWR and 48PWR are fairly noisy. /Benny ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
How are you getting these 80 or 120mm fans in a 1U chassis? Remember you got barely 45mm to play with at the back and front of the switch. How are you going to mount a 80mm or 120mm fan on there? Are you assuming that the units mounted above (or below) your switch is a short 1U? You can't assume that... I guess one shouldn't assume as a rule, but... If I were concerned about noise, it would be because I am positioning this near people, and not in a densely-packed rack. Thus I would be OK eliminating the 1U constraint. I think these tend to be distinct deployment scenarios. And thinking about that, do PoE switches tend to be deployed near people? You tell me. I'd like to find a quiet 24-port PoE switch - even at 100 Mb. smime.p7s Description: S/MIME Cryptographic Signature ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
2009/2/2 Singer XJ Wang w...@pythian.com [snipped] You can do that by using fans other than the tiny, whiney, 40mm fans that vibrate at 6000 to 18,000 Hz. A couple of 80 or 120 mm muffin fans at the back or front, pushing air in (hence the deep dimensions), but the top and bottom would need recesses to allow sufficient airflow when the positions above and below are filled. How are you getting these 80 or 120mm fans in a 1U chassis? Remember you got barely 45mm to play with at the back and front of the switch. How are you going to mount a 80mm or 120mm fan on there? Are you assuming that the units mounted above (or below) your switch is a short 1U? You can't assume that... Ever heared of a centrifugal fan? ;-) Chris ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
Gordon Henderson wrote: On Mon, 2 Feb 2009, Steve Underwood wrote: Bernd Felsche wrote: Ian Cowley i...@moffat.co.uk wrote: Beware PoE switches that can't handle Class 3 (15W) on all ports. Most have fans because 24 (or 48) x 15W is hot! That's the power supplied .. which'd be at the far end of the wire. The efficiency of the PSU plays a big part in the heat dissipation. The push to compact dimensions doesn't help ... a 400W or thereabouts PSU with 24 independent outputs in 1U height? I suppose if the switch were quite deep it could be workable and quiet. The problem isn't simply of being fanless. But being quiet. Preferably below 32 dBA at 1 metres for most offices. You can do that by using fans other than the tiny, whiney, 40mm fans that vibrate at 6000 to 18,000 Hz. A couple of 80 or 120 mm muffin fans at the back or front, pushing air in (hence the deep dimensions), but the top and bottom would need recesses to allow sufficient airflow when the positions above and below are filled. So, size does matter after all. :-) 24 x 15W = 360W. Its not that big a supply really, and spread across a 1U case its not that dense a supply. A 360W desktop PC supply can be pretty quiet, so its sad none of the 1U chassis supplies are. Probably if they used a large impeller fan they could get the noise down. I guess they assume these things will be in cupboards or data centres where nobody cares. This is a poor assumption. I think you might be missing what Bernd Felsche wrote - 24 * 15W is indeed 360W, but the power supply will not be dissipating that - the phones at the far-end will. A modern switched mode PSU ought to be more than 90% efficient, so that means the PSU should only be dissipating 30 watts or so. Easy enough to keep cool with little or no fans. Same for those PC PSUs - the PSUs themselves really shouldn't be dissipating that much power (as heat). I suspect some early PSU makers just put fans in because. I think you definitely are missing what I wrote. I said its a 360W power supply, which it is. Its dissipation should be comparable with a 360W PC supply, though the per port power control will add a bit to the total dissipation. Very few supplies are 90% efficient, and they only hit their peak efficiency at some magic load settings. An efficiency of 70-80% is far more likely. Try looking at some specs for PC supplies. Early ethernet switches did get hot - because of all the switching going on in their chips, so it wouldn't surprise me if most of the heat coming out of them was actuall the Ethernet part of it - esepcially at Gb levels than the power convertors... Most current Gig-E chips get hot when plugged into a Gig-E device, but run very cool when plugged into a 100M device. A lot Gig-E stuff actually overheats badly in such circumstances. If the sales of Gig-E switches rises, a lot of people are going to find their motherboards roasting. :-) Steve ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
Honestly, how are you guys expecting a 24 Port POE to be fanless? Lets start with some logical points here: 1) 24 Ports x 15.4W/Port = 369.4Watts + Switch Power = ~400Watts... now Power Supply isn't that efficient so you're getting probably a 500Watt Power Supply (assuming 80%)... 2) with a 1U chassis, you can't blow air up or down... only front and back.. so you're stuck with a 40mm fan.. ... Benny Amorsen wrote: Paul Hales pdha...@optusnet.com.au writes: My memory of a HP procurve (a 2626 PWR from memory) was that it was quite noisy - have they changed? The 2626 is either extremely noisy or fairly noisy, depending on which you happen to get. Luck of the draw; I haven't found a way to predict it. The 2650 is almost always in the fairly category. However, the 2610-24 is fanless, which sounds great. Except the PoE versions aren't fanless. The 2610-24/12PWR is not THAT bad unless it gets hot, the 24PWR and 48PWR are fairly noisy. /Benny ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users begin:vcard fn:Singer Wang n:Wang;Singer org:The Pythian Group;Team 13 adr:116 Albert Street;;Suite 1000;Ottawa;Ontario;K1P 5G3;Canada email;internet:w...@pythian.com title:System and Database Administrator tel;work:(613) 565-8696 x298 tel;fax:(613) 565-8710 x-mozilla-html:TRUE url:http://www.pythian.com version:2.1 end:vcard ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
Okay, point out one reasonably priced PoE switch that has it. Christian Victor wrote: 2009/2/2 Singer XJ Wang w...@pythian.com mailto:w...@pythian.com [snipped] You can do that by using fans other than the tiny, whiney, 40mm fans that vibrate at 6000 to 18,000 Hz. A couple of 80 or 120 mm muffin fans at the back or front, pushing air in (hence the deep dimensions), but the top and bottom would need recesses to allow sufficient airflow when the positions above and below are filled. How are you getting these 80 or 120mm fans in a 1U chassis? Remember you got barely 45mm to play with at the back and front of the switch. How are you going to mount a 80mm or 120mm fan on there? Are you assuming that the units mounted above (or below) your switch is a short 1U? You can't assume that... Ever heared of a centrifugal fan? ;-) Chris begin:vcard fn:Singer Wang n:Wang;Singer org:The Pythian Group;Team 13 adr:116 Albert Street;;Suite 1000;Ottawa;Ontario;K1P 5G3;Canada email;internet:w...@pythian.com title:System and Database Administrator tel;work:(613) 565-8696 x298 tel;fax:(613) 565-8710 x-mozilla-html:TRUE url:http://www.pythian.com version:2.1 end:vcard ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
Steve Underwood ste...@coppice.org wrote: Gordon Henderson wrote: On Mon, 2 Feb 2009, Steve Underwood wrote: Bernd Felsche wrote: Ian Cowley i...@moffat.co.uk wrote: Beware PoE switches that can't handle Class 3 (15W) on all ports. Most have fans because 24 (or 48) x 15W is hot! That's the power supplied .. which'd be at the far end of the wire. The efficiency of the PSU plays a big part in the heat dissipation. The push to compact dimensions doesn't help ... a 400W or thereabouts PSU with 24 independent outputs in 1U height? I suppose if the switch were quite deep it could be workable and quiet. The problem isn't simply of being fanless. But being quiet. Preferably below 32 dBA at 1 metres for most offices. You can do that by using fans other than the tiny, whiney, 40mm fans that vibrate at 6000 to 18,000 Hz. A couple of 80 or 120 mm muffin fans at the back or front, pushing air in (hence the deep dimensions), but the top and bottom would need recesses to allow sufficient airflow when the positions above and below are filled. So, size does matter after all. :-) 24 x 15W = 360W. Its not that big a supply really, and spread across a 1U case its not that dense a supply. A 360W desktop PC supply can be pretty quiet, so its sad none of the 1U chassis supplies are. Probably if they used a large impeller fan they could get the noise down. I guess they assume these things will be in cupboards or data centres where nobody cares. This is a poor assumption. I think you might be missing what Bernd Felsche wrote - 24 * 15W is indeed 360W, but the power supply will not be dissipating that - the phones at the far-end will. A modern switched mode PSU ought to be more than 90% efficient, so that means the PSU should only be dissipating 30 watts or so. Easy enough to keep cool with little or no fans. Same for those PC PSUs - the PSUs themselves really shouldn't be dissipating that much power (as heat). I suspect some early PSU makers just put fans in because. I think you definitely are missing what I wrote. I said its a 360W power supply, which it is. Its dissipation should be comparable with a 360W PC supply, though the per port power control will add a bit to the total dissipation. Very few supplies are 90% efficient, and they only hit their peak efficiency at some magic load settings. An efficiency of 70-80% is far more likely. Try looking at some specs for PC supplies. The PoE switches tend to use better than the cheapest-available technology. 90% is fairly easy to achieve except at the bottom end of the load capacity range ... i.e. when power drawn is only a few percent of the rated capacity. Efficiency can vary significantly, depending on load. The other point which I made, in addition to the 360W being dissipated by the appliances, is that there is a power supply for each PoE port. Each independently-regulated and and current limited, commonly even under software control as is seems that most of these sorts of switches are managed/managable. All of them appear to sense automatically if the connected appliance requires PoE. Even without being gigabit speed at each PoE port, the independent PSU per port alone increases the heat dissipation; probably in the order of half to one watt per port; within the switch. The designers of the switches seem to be able to incorporate all sorts of clever tricks in their management interfaces. But most don't automatically control the fans according to the temperature. -- /\ Bernd Felsche - Innovative Reckoning, Perth, Western Australia \ / ASCII ribbon campaign | Religion is regarded by the common people X against HTML mail | as true, by the wise as false, and by the / \ and postings | rulers as useful. -- Seneca the Younger ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
Wilton Helm wh...@compuserve.com wrote: A modern switched mode PSU ought to be more than 90% efficient, In theory, yes, in practice, not likely. It is harder to get high efficiency from an isolated supply than a non-isolated one. I get ads from IC manufacturers all the time about there 90 to 95% efficient solutions, but these are boost or buck regulators--non-isolated. State of the art in commercial practice for isolated supplies is around 80 to 85%, and typical commercial practice is more like 70 to 80%. The per-port regulators would be non-isolated. Probably feeding off an internal 48V bus. Now you have more like 60 watts of heat radiating from this power supply. Go stick a 60 watt light bulb (incandescent) in a small metal box and see how easy it is to keep cool. Well, the bulb has a peak permissible operation temperature of about 160 degrees C ... so likely no extra cooling required. :-) -- /\ Bernd Felsche - Innovative Reckoning, Perth, Western Australia \ / ASCII ribbon campaign | Religion is regarded by the common people X against HTML mail | as true, by the wise as false, and by the / \ and postings | rulers as useful. -- Seneca the Younger ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
Singer XJ Wang w...@pythian.com wrote: Honestly, how are you guys expecting a 24 Port POE to be fanless? Lets start with some logical points here: 1) 24 Ports x 15.4W/Port = 369.4Watts + Switch Power = ~400Watts... now Power Supply isn't that efficient so you're getting probably a 500Watt Power Supply (assuming 80%)... It'd still be a 400W PSU if it supplies 400W. 2) with a 1U chassis, you can't blow air up or down... only front and back.. so you're stuck with a 40mm fan.. And the sides... ... you can fit a muffin fan horizontally as suggested and allow it to draw in or to blow air at the top or botton within the height of the 1U. Muffin fans are 25 to 35 mm high. Placed centrally, the fans can draw in air from around the port connectors on the front panel (if the back-end of the connectors is sealed!) and blow into the PSU, exiting at the back. This also helps to reduce the little fan noise that remains, leaving mostly white noise from the air flow itself (unless you install whistles). -- /\ Bernd Felsche - Innovative Reckoning, Perth, Western Australia \ / ASCII ribbon campaign | Religion is regarded by the common people X against HTML mail | as true, by the wise as false, and by the / \ and postings | rulers as useful. -- Seneca the Younger ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
Lets start with some logical points here: 1) 24 Ports x 15.4W/Port = 369.4Watts + Switch Power = ~400Watts... now Power Supply isn't that efficient so you're getting probably a 500Watt Power Supply (assuming 80%)... It'd still be a 400W PSU if it supplies 400W. 2) with a 1U chassis, you can't blow air up or down... only front and back.. so you're stuck with a 40mm fan.. And the sides... ... you can fit a muffin fan horizontally as suggested and allow it to draw in or to blow air at the top or botton within the height of the 1U. Muffin fans are 25 to 35 mm high. This whole thread is getting stupid and I'd hope the people involved would desist from this O/T drivel. If you want a switch go to the shop, hand over some money and buy one... Like every one else does and they're perfectly happy with their purchase. The O.P. is not going to change the world and quite frankly the designer/manufacturer of the product knows a lot more about the subject then they do ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
This whole thread is getting stupid and I'd hope the people involved would desist from this O/T drivel. If you want a switch go to the shop, hand over some money and buy one... Like every one else does and they're perfectly happy with their purchase. The O.P. is not going to change the world and quite frankly the designer/manufacturer of the product knows a lot more about the subject then they do It's really just a lot of hot air. (ducks and runs for cover) PaulH ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
Check out the HP ProCurve Switch 2610-24-PWR -Original Message- From: asterisk-users-boun...@lists.digium.com [mailto:asterisk-users-boun...@lists.digium.com] On Behalf Of Chris Bagnall Sent: February 1, 2009 6:58 AM To: Asterisk Users List Subject: Re: [asterisk-users] Quiet 24 port POE gig switch I can find FANLESS 24 port PoE 10/100 That's an achievement in itself. Can you post details - I have quite a few locations where that might be useful... TIA. Regards, Chris ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
I can find FANLESS 24 port PoE 10/100 That's an achievement in itself. Can you post details - I have quite a few locations where that might be useful... TIA. Regards, Chris ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
Beware PoE switches that can't handle Class 3 (15W) on all ports. Most have fans because 24 (or 48) x 15W is hot! IanC -Original Message- From: asterisk-users-boun...@lists.digium.com [mailto:asterisk-users-boun...@lists.digium.com] On Behalf Of Chris Bagnall Sent: Sunday, February 01, 2009 11:58 AM To: 'Asterisk Users Mailing List - Non-Commercial Discussion' Subject: Re: [asterisk-users] Quiet 24 port POE gig switch I can find FANLESS 24 port PoE 10/100 That's an achievement in itself. Can you post details - I have quite a few locations where that might be useful... TIA. Regards, Chris ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __ Moffat Communications Limited is a wholly owned Company of Grant Thornton UK LLP, registered in England and Wales, with number 2355810, and whose registered office is Grant Thornton House, Melton Street, Euston Square, London, NW1 2EP. Moffat Communications Limited is registered to carry out Business and management consultancy. When addressed to our clients, any opinions or advice set out in this email and any attachments are subject to the terms and conditions expressed in the relevant Moffat Communications Limited client engagement letter. Opinions, conclusions and other information in this email which do not relate to the official business of the firm are neither given nor endorsed by it. Any personal views expressed in this message are not necessarily the views of Moffat Communications Limited. This message is intended only for the individual or entity to which it is addressed and may contain information that is private and confidential. If you are not the intended recipient, employee or agent responsible for delivering the message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication and its attachments is strictly prohibited. If you have received this communication and its attachments in error, please return the original message and attachments to us using the reply facility on e-mail. Moffat Communications Limited has scanned this email for viruses but does not accept any responsibility once this email has been transmitted. You should scan attachments (if any) for viruses. Any person communicating with us by e-mail will be deemed to have accepted the risks associated with sending information by e-mail being interception, amendment and loss, and also the consequences of incomplete or late delivery. __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __ ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
2009/1/31 OCG Technical Support supp...@ocg.ca A little off topic but I need to put a 24 port Gig PoE switch into a small office – no computer room / rack etc. All CAT5 terminates near the owners desk (smart huh?). I want to put a PoE switch in place, with 24 ports and Gig speed. Everyone I've researched so far is LOUD... Anyone know of a quiet one? Thanks ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users I can't remember the exact model but I used a Cisco catalyst switch for a class and after reboot, it was very quiet. ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
As far as I know all POE switches are quite noisy, they need to cool the extra power consumed by the POE and hence they will run warmer than other switch. I know Cisco, 3COM, are very noisy but you can try other cheaper brand like levelone or other to see if they have fans inside the switch. Good Luck -Original Message- From: asterisk-users-boun...@lists.digium.com [mailto:asterisk-users-boun...@lists.digium.com] On Behalf Of Olivier Sent: Monday, February 02, 2009 1:06 AM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: Re: [asterisk-users] Quiet 24 port POE gig switch 2009/1/31 OCG Technical Support supp...@ocg.ca A little off topic but I need to put a 24 port Gig PoE switch into a small office - no computer room / rack etc. All CAT5 terminates near the owners desk (smart huh?). I want to put a PoE switch in place, with 24 ports and Gig speed. Everyone I've researched so far is LOUD... Anyone know of a quiet one? Thanks ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users I can't remember the exact model but I used a Cisco catalyst switch for a class and after reboot, it was very quiet. ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
I guess one would have to ask whether 1000 Gb is necessary. That's a lot of bandwidth. It might make sense to use it for central distribution. There are also some that have one or two 1000 Gb ports that might be appropriate for trunking and the rest 100 Mb which is probably fast enough for terminal nodes. That combination would be less power hungry. On the other hand if this is for HDTV multichannel distribution, then I retract what I said. Wilton ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
Ian Cowley i...@moffat.co.uk wrote: Beware PoE switches that can't handle Class 3 (15W) on all ports. Most have fans because 24 (or 48) x 15W is hot! That's the power supplied .. which'd be at the far end of the wire. The efficiency of the PSU plays a big part in the heat dissipation. The push to compact dimensions doesn't help ... a 400W or thereabouts PSU with 24 independent outputs in 1U height? I suppose if the switch were quite deep it could be workable and quiet. The problem isn't simply of being fanless. But being quiet. Preferably below 32 dBA at 1 metres for most offices. You can do that by using fans other than the tiny, whiney, 40mm fans that vibrate at 6000 to 18,000 Hz. A couple of 80 or 120 mm muffin fans at the back or front, pushing air in (hence the deep dimensions), but the top and bottom would need recesses to allow sufficient airflow when the positions above and below are filled. -- /\ Bernd Felsche - Innovative Reckoning, Perth, Western Australia \ / ASCII ribbon campaign | Religion is regarded by the common people X against HTML mail | as true, by the wise as false, and by the / \ and postings | rulers as useful. -- Seneca the Younger ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
My memory of a HP procurve (a 2626 PWR from memory) was that it was quite noisy - have they changed? PaulH OCG Technical Support wrote: Check out the HP ProCurve Switch 2610-24-PWR -Original Message- From: asterisk-users-boun...@lists.digium.com [mailto:asterisk-users-boun...@lists.digium.com] On Behalf Of Chris Bagnall Sent: February 1, 2009 6:58 AM To: Asterisk Users List Subject: Re: [asterisk-users] Quiet 24 port POE gig switch I can find FANLESS 24 port PoE 10/100 That's an achievement in itself. Can you post details - I have quite a few locations where that might be useful... TIA. Regards, Chris ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
Bernd Felsche wrote: Ian Cowley i...@moffat.co.uk wrote: Beware PoE switches that can't handle Class 3 (15W) on all ports. Most have fans because 24 (or 48) x 15W is hot! That's the power supplied .. which'd be at the far end of the wire. The efficiency of the PSU plays a big part in the heat dissipation. The push to compact dimensions doesn't help ... a 400W or thereabouts PSU with 24 independent outputs in 1U height? I suppose if the switch were quite deep it could be workable and quiet. The problem isn't simply of being fanless. But being quiet. Preferably below 32 dBA at 1 metres for most offices. You can do that by using fans other than the tiny, whiney, 40mm fans that vibrate at 6000 to 18,000 Hz. A couple of 80 or 120 mm muffin fans at the back or front, pushing air in (hence the deep dimensions), but the top and bottom would need recesses to allow sufficient airflow when the positions above and below are filled. So, size does matter after all. :-) 24 x 15W = 360W. Its not that big a supply really, and spread across a 1U case its not that dense a supply. A 360W desktop PC supply can be pretty quiet, so its sad none of the 1U chassis supplies are. Probably if they used a large impeller fan they could get the noise down. I guess they assume these things will be in cupboards or data centres where nobody cares. This is a poor assumption. Regards, Steve ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
My google search says fanless... -Original Message- From: asterisk-users-boun...@lists.digium.com [mailto:asterisk-users-boun...@lists.digium.com] On Behalf Of Paul Hales Sent: February 1, 2009 6:49 PM To: Asterisk Users List Subject: Re: [asterisk-users] Quiet 24 port POE gig switch Importance: High My memory of a HP procurve (a 2626 PWR from memory) was that it was quite noisy - have they changed? PaulH OCG Technical Support wrote: Check out the HP ProCurve Switch 2610-24-PWR -Original Message- From: asterisk-users-boun...@lists.digium.com [mailto:asterisk-users-boun...@lists.digium.com] On Behalf Of Chris Bagnall Sent: February 1, 2009 6:58 AM To: Asterisk Users List Subject: Re: [asterisk-users] Quiet 24 port POE gig switch I can find FANLESS 24 port PoE 10/100 That's an achievement in itself. Can you post details - I have quite a few locations where that might be useful... TIA. Regards, Chris ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
2009/2/2 Steve Underwood ste...@coppice.org Bernd Felsche wrote: Ian Cowley i...@moffat.co.uk wrote: Beware PoE switches that can't handle Class 3 (15W) on all ports. Most have fans because 24 (or 48) x 15W is hot! That's the power supplied .. which'd be at the far end of the wire. The efficiency of the PSU plays a big part in the heat dissipation. The push to compact dimensions doesn't help ... a 400W or thereabouts PSU with 24 independent outputs in 1U height? I suppose if the switch were quite deep it could be workable and quiet. The problem isn't simply of being fanless. But being quiet. Preferably below 32 dBA at 1 metres for most offices. You can do that by using fans other than the tiny, whiney, 40mm fans that vibrate at 6000 to 18,000 Hz. A couple of 80 or 120 mm muffin fans at the back or front, pushing air in (hence the deep dimensions), but the top and bottom would need recesses to allow sufficient airflow when the positions above and below are filled. So, size does matter after all. :-) 24 x 15W = 360W. Its not that big a supply really, and spread across a 1U case its not that dense a supply. A 360W desktop PC supply can be pretty quiet, so its sad none of the 1U chassis supplies are. Probably if they used a large impeller fan they could get the noise down. I guess they assume these things will be in cupboards or data centres where nobody cares. This is a poor assumption. The problem is squeezing fans in that can push enough air to keep it cool... For a 1U device, you have only 4.445cm to work with, with a 4mm fan, that would be 2.2mm of space for casing etc above and below, reasonably tight already... A quiet 80mm fan as you may find in a PC PSU that puts out somewhere between 15-20dBA of noise will typically move between 20 and 30 cfm of air... A quiet 120mm fan at the same noise levels would typically move between 30 and 50 cfm of air and a quiet 40mm at those levels would move about 5 cfm of air... Obviously, they aren't using quiet 40mm fans... To get the airflow of the quiet 80mm fans, a 40mm fan has to go very fast and you're looking at noise levels of approx 40-60dBA, not exactly quiet, but, that's not all, even if the fan was silent, forcing the air through the small cramped chassis of a 1U device is going to be noisy... The assumption made when they make these devices is that the vast majority of people will put this kit somewhere out of the way in a likely temperature controlled, reasonably sound insulated environment, with the rest of their hardware that lives hidden from people... These people will likely prefer that kit uses the space as efficiently as possible, so, squeezing as much functionality into as few rack units as possible is important... They have typically made a good assumption in this I would say... Admittedly, people who are planning an office for their first time may more commonly neglect IT hardware, it's requirements (and those of those people around it), from an IT standpoint, it's a significant pain to deal with, but, in most cases I've seen, it's something that's considered very carefully if planning an office in the future... I suspect the lack of larger quieter units in the market is reflective of the much lower demand for these, somewhat specialised devices... On the otherhand, soundproofed rack cabinets that have integrated cooling and look nice/plain enough that they don't scare people in an office should be generic enough that there would, I suspect, be sufficient demand from those that didn't consider IT requirements when fitting out an office to justify making them... d ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
Hello, I need to put a 24 port Gig PoE switch into a small office – no computer room / rack etc. All CAT5 terminates near the owners desk (smart huh?). I had a similar problem some days ago. 24-port GBit Switch in the middle of a classroom... I ended up with a kind of semi-loud setup: I bought a 3Com 3CBLSG switch (this is without PoE, but there is a PoE version of it). There are two quite noisy 40x40x10 fans inside. I replaced the two with one 40x40x20 ebmPapst silent fan (model 412/2, 18dB), left the other fan offline and mounted the whole thing vertically so that convection supports the remaining fan. I tried with two silent fans (enough space inside), but this still was too noisy. Some measurement indicates the cooling is sufficient this way. But understand that I've no long term data, as I installed this setup just two weeks ago. And of course your warranty is void ;-) Greets, Claus -- CHECON EDV-Consulting und Redaktion Claus Herwig * Barer Straße 70 * 80799 München +49 89 27826981 * Fax 27826982 * c.her...@checon.de ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
You will have a hard time finding a 24 port POE without fans - too high of a power density. Do you really need 24 ports? perhaps a 12x12 otherwise multiple 8 or 12 port models may work Do let us know if you find a 24 port without fans. On Jan 31, 2009, at 2:06 PM, Claus Herwig wrote: Hello, I need to put a 24 port Gig PoE switch into a small office – no computer room / rack etc. All CAT5 terminates near the owners desk (smart huh?). I had a similar problem some days ago. 24-port GBit Switch in the middle of a classroom... I ended up with a kind of semi-loud setup: I bought a 3Com 3CBLSG switch (this is without PoE, but there is a PoE version of it). There are two quite noisy 40x40x10 fans inside. I replaced the two with one 40x40x20 ebmPapst silent fan (model 412/2, 18dB), left the other fan offline and mounted the whole thing vertically so that convection supports the remaining fan. I tried with two silent fans (enough space inside), but this still was too noisy. Some measurement indicates the cooling is sufficient this way. But understand that I've no long term data, as I installed this setup just two weeks ago. And of course your warranty is void ;-) Greets, Claus -- CHECON EDV-Consulting und Redaktion Claus Herwig * Barer Straße 70 * 80799 München +49 89 27826981 * Fax 27826982 * c.her...@checon.de ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
OCG Technical Support wrote: A little off topic but I need to put a 24 port Gig PoE switch into a small office – no computer room / rack etc. All CAT5 terminates near the owners desk (smart huh?). I want to put a PoE switch in place, with 24 ports and Gig speed. Everyone I’ve researched so far is LOUD... Chances of finding a PoE switch that is quiet out of the box is about as good as finding a government 'worker'. It's kind of an oxymoron. Of the switches I've used, the Linksys/Cisco line was the loudest. Dlink's were quieter, but still not something you'd want sitting next to a desk. About the only fanless PoE switches I've seen are the smaller Netgear's, but they are not Gigabit. Darrick ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] Quiet 24 port POE gig switch
I can find FANLESS 24 port PoE 10/100, or FANLESS 24 port non-POE 10/100/1000 I guess I'll just have to wait for newer chips..till then dropping down to 10/100 -Original Message- From: asterisk-users-boun...@lists.digium.com [mailto:asterisk-users-boun...@lists.digium.com] On Behalf Of Darrick Hartman Sent: January 31, 2009 10:02 PM To: Asterisk Users List Subject: Re: [asterisk-users] Quiet 24 port POE gig switch Importance: High OCG Technical Support wrote: A little off topic but I need to put a 24 port Gig PoE switch into a small office - no computer room / rack etc. All CAT5 terminates near the owners desk (smart huh?). I want to put a PoE switch in place, with 24 ports and Gig speed. Everyone I've researched so far is LOUD... Chances of finding a PoE switch that is quiet out of the box is about as good as finding a government 'worker'. It's kind of an oxymoron. Of the switches I've used, the Linksys/Cisco line was the loudest. Dlink's were quieter, but still not something you'd want sitting next to a desk. About the only fanless PoE switches I've seen are the smaller Netgear's, but they are not Gigabit. Darrick ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
