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Enterprise Switch Recommendation

Last response: in Networking
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December 28, 2009 6:45:46 PM

I have a small business network. There is a Dell server running SBS 2003, around seven desktops and five or ten other network devices such as printers. Here is my network layout: The server is in building X. Switch A is connected to the server. The wire runs something like 150' to switch B. Then about 50' to switch C. From there, the wire goes outside approximately 320' into building Y where it connects to switch D. I have had problems with switch C dying on me. Can someone recommend an enterprise switch that can handle taking the signal 320'? Switch A, B and D are gigabit switches so I would probably like to have switch C be gigabit also. I only need two ports on this switch because there is no chance of adding anything else in this location. This switch is in a semi-heated shop. I don't think the temp would get below around 50 degrees F so I don't think that is the problem.

Thank you in advance for any help you can give!
December 28, 2009 8:27:27 PM

ok, this is a shot in the dark since I'm not an electrician. but....

I remember reading an article from APC about possible issues with switches and alternate power sources.

Eg. Switch 1 is in Building 1 where the wall voltage is 109 volts
Switch 2 in in building 2 where the voltage is 112 volts.

The difference in voltage causes power to trickle across from one switch to the other via the network cable. This power differential over time can cause damage to network equipment.

Obviously APC gave this as a reason to use UPS on the switches to regulate the voltages.

Anyone?

Otherwise, my old job used HP switches just fine for greater than 100 meters stretches, and they cleared those 100+ meters using only 4 of the 8 wires and the other 8 wires where used for another connection. So they put two Ethernet gigabit lines over only 8 wires(instead of 16) and over 100 meters. No problems ever.

All intra building was optical though and the "doubled" up lines were because of a few old buildings where rewiring was near impossible or not worth the time of you could do a "patch" job.
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December 29, 2009 6:29:43 PM

I do have UPSs on both switches. But, I don't think they regulate the voltage to that close of tolerances. I will check the voltages and see what I have on both ends.

I will also look at HP switches. Does anyone have any other recommendations or thoughts on specific switches that might work for my situation?
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December 29, 2009 7:22:07 PM

What I've seen a few times is a voltage differential between the ground on outlets (15 VAC is the maximum that I ever saw; a couple volts usually doesn't cause problems).
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December 30, 2009 4:03:30 PM

I would look into upgrading intra-building lines to optical when you can. Sorry I couldn't help more. I don't know a whole lot about diagnosing switch/router problems.. :*(

I wonder if there's any tools to test line voltage/etc to make sure everything is in at least normal levels.
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December 31, 2009 12:38:50 AM

i agree with Kewlx25. This problem is exactly why optical fiber lines were invented. Sure you can clear 100+ meters using less pairs in the cabling but even that has its limit. your trying to bridge a 320yd gap. the recommended maximum length for ethernet purposes is 100m. your pushing almost 300m. an enterprise switch will not help you here, a switch is not meant to "strengthen" a signal. To do this you are either going to need a repeater device somewhere in between your connection. id recommend two repeaters if you go that route. or your gona need to use fiber. the problem here is distance, not electrical.
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December 31, 2009 4:11:06 AM

Actually, the distance is about 320 feet. It's less than that but because of the wire "twist" it measures around 320 feet.

What do you mean by "repeater device"? How much do these cost? Any specific model recommendations?
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December 31, 2009 5:42:44 AM

ah sorry i dont know what i was thinking. i was thinkin yards instead of feet. 320 feet is within the recommended ethernet limit. so you should be fine there. first of all since your C switch is not gigabit, then all traffic from C and D are going to be at 100mbps at the fastest. so your losing out on some performance there, sometimes i have run into the problem when if one switch in the middle of the network is not the same Ethernet speed as the ones before it, it cant cause some problems, especially if the switches above it are as faster speeds, which is your case exactly. typically the switches will detect the lowest speed switch in the network and autoconfig to that speed but sometimes it configures wrong and then you have your probelm of the switch dying and dropping packets. My best answer would be to replace Switch C with a gigabit switch, this would fix your problem as well as boost your traffic speed coming from switch D
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January 4, 2010 6:13:13 PM

Thanks to everyone for your help. I just ordered an HP Procurve 1400-8G. I has really good reviews and a LIFETIME warranty. So, we'll see how it works!
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January 7, 2010 1:50:10 PM

It appears my problem was with one port in switch D in building Y. I finally checked the voltages. Yes, the voltage is higher in building Y. Yesterday, the shop was shutdown and the voltage was around 128 as high as 132. I believe I recall one of our shop maintenance guys telling me he raised the voltage because it drops so much when all the machines are running. If I recall correctly, my switch problems have always occurred first thing in the morning, and particularly Monday mornings, when the voltage would have been higher over night and over the weekend (because the machines are not running). This definitely gives credence to the theory of the voltage difference causing damage to the network switches. Since the majority of my computer equipment and network switches are in building Y where the voltage is high, do I need to put voltage regulation on EVERY device that is connected to the network? If not, the voltage difference will still exist! Any thoughts?
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January 7, 2010 2:02:18 PM

You could use APC backup power units. They will trim excessive voltage from the line and also provide battery backup power if needed.
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January 7, 2010 4:58:50 PM

It might not actually be the building voltage but the difference in ground? This might be what I was thinking about, it's hard to google.

Here's a snipit of something I found on the net, but not from the same APC article that I can't find yet.

"What those grounding currents and voltage differences can do ?

Higher currents can cause more serious problems like sparking in connections, damages equipment and burned wiring. My own experience on th field is limited to sparking connectors, heating cables and damaged computer serial port cards. I have read about burned signal cables and smoking computers because of the ground differentials and large currents caused by them. "

I would assume intra-building network cabling can increase the chances of theses kinds of things happening, not to say this *is* the problem.
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