11-25-2010 03:02 AM - edited 03-16-2019 02:06 AM
Hi
We have an issue where some user(s) have disconnected there phone (7941 phones) and then reconnected there phone to the same network cable (back to the way it was) ....and the phone has not come back on line - no power to the phone.
I can move the phone to another switch port and all is ok but do you know what is causing this?
It is difficult to see exactly which port the phone came from so I can have a look at the interface status as there is around 400 phones connected to the back of the Cisco 4500 switch
I don't see any ports that are in an err-disabled state however I did notice there are some ports in an inactive state
Any thoughts?
Regards
James
11-25-2010 07:03 AM
I have seen this type of behavior when you have reached the maximum PoE capabilities of the switch under it's current configuration. You should see syslog messages that power was denied. Also a "show power" command will show you the used vs. maximum available for Inline Power. If you are low it cannot supply power.
The best thing you can do is ensure it's running on 208v or higher feeds. The power capacity of the switch is limited when running on 120v or lower. The Cisco Power Calculator can help you see what capacity you have based on your hardware purchase.
11-25-2010 08:13 AM
Hi
Thanks for your reply
below is a snippet from show power command
MERA0VOIP01#show power available
Power Summary Maximum
(in Watts) Used Available
---------------------- ---- ---------
System Power (12V) 755 1360
Inline Power (-50V) 1050 1400
Backplane Power (3.3V) 40 40
---------------------- --- ---------
Total 1845 2800
---------------------------------------------------------------------------
------------------------------------------------------------------------------
MERA0VOIP01#sh power
Power Fan Inline
Supply Model No Type Status Sensor Status
------ ---------------- --------- ----------- ------- -------
PS1 PWR-C45-2800AC AC 2800W good good good
PS2 PWR-C45-2800AC AC 2800W good good good
Power supplies needed by system : 1
Power supplies currently available : 2
Power Summary Maximum
(in Watts) Used Available
---------------------- ---- ---------
System Power (12V) 755 1360
Inline Power (-50V) 1033 1400
Backplane Power (3.3V) 40 40
---------------------- ---- ---------
Total 1828 2800
11-25-2010 01:29 PM
Have you tried running TDR on the line?
11-30-2010 05:00 AM
Hi All,
This issue has been identified as a faulty module on the Cisco 4500 switch
- module swapped out and issue resolved
James
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