When PC shuts down VOIP goes down as well

[bigmac31]

Hello,

I have an interesting situation that I haven't encountered before. We have a PC that is connected to a Cisco IP phone that in turn connects to the wall jack for the connectivity. For whatever reason when the user closes the lid on the laptop the phone shuts off. I looked at the POE settings on the switch and there is nothing indicating it is a power setting. I have never seen this before and it only occurs at 1 out of 16 locations that I manage. Any suggestions would be much appreciated.

Thanks,

BigMac

[Adam Pawlowski]

I have had the PC state cause the phone to drop off and re-register for whatever reason. I believe you can set it to synchoronize the port speeds but that is not the default as far as I am aware. That will also send a link down message if you use some sort of NAC that monitors those things. Can't think of any reason that this would drive the PoE to turn off unless this is doing something funky but you'd see a power inline syslog message from the switch if it is not happy.

[saif musa]

bigmac31,

Does the phone reset or shutdown when you close the led of attached PC? 

[bigmac31]

The phone resets and the current calls attempt to go into call preservation mode.

[Rob Huffman]

Hi BigMac,

Just to add a note to the good tips from Adam & Saif (+5)

It could be this bug;

Phone restart when PC attached reboots

CSCtj47812

Description

Symptom:
When a PC attached to a phone switch port reboots the phone will do a slow soft restart. The computer is plugged into the PC port. They have confirmed this to happen on both PC and Mac and on 79XX, 89XX and 99XX phones.

Conditions:
They believe they have determined what is causing this issue. The following new feature is causing it "Automatic Port Synchronization". If this is set to enabled. When the computer is shutdown or restarted it must be dropping the network speed from 1000 to 10 mbit and the phone then does a reset to match the speeds. Also note, all computers at their site have Wake on LAN turned on by their IT by default on the machines in the BIOS.

Cheers!

Rob