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Ethernet Disconnected

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teltonman

IS-IT--Management
Jan 24, 2011
53
I keep getting this message with a particular phone. I have plugged it into several known to be good working jacks! Any idea's please?
 
Do you get that if you plug it in directly into the switch? Have you swapped the patch cord or just jacks?
 
whykap is right. I had the same issues a couple times in the past and it was the cable even though a PC seemed to be working fine on it before we installed IP phones. We reterminated the cable on both ends and the phone came up and worked.
 
This is going to sound strange, but it is true.

Make SURE you have the PC plugged into the PC port on the phone and the other jack (on the phone) plugged into the switch port. On SOME phones we have noticed that if they are reversed the phone and CPU will work as long as the PC is turned on. When the PC is OFF, and the cables are wrong, you sometimes get the ETHERNET DISCONNECTED error message.

In our case the was happening on 7911 phones but not others.



Network Administrator - Communications & Security Services
Merrillville Commuity School Corp.
276 East 68th Place
Merrillville, IN 46910
 
the times I've run into the Ethernet Disconnected message, so far 100% of the time it has been a cabling issue. Either a patch cable or the drop itself. PC would work fine, but the PC's seem to be far more tolerant of cable faults...ie, faults on pins 457and8. The phones are not as tolerant.
 
normally, the PC will need only 2 cable pairs from the ethernet bundle. (normal ethernet connection)
Now, If you are using Power over Ethernet for phones like I do , then all 4 cable pairs will need to be connected end-to-end (switch to phone ) If at least 1 of the cable is not terminated or damaged, the phone goes down or gives you Ethernet disconnected error

this can explain why PCs are working fine, and phones are not working.
it has always been cabling issue for me till now.

also, from experience, any new data point which is being laid, I use an IP Phone to test it.
happened to me, the guy tested the a new data point with a laptop, but my phone doesnt light up, and he says he did his homework well. !
 
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