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New Member

Phones rebooting on hang up

I am having an issue with a 3560 24-port switch with IP phones hanging off it.

After making a call, some of the phones are rebooting when the handset is replaced.

Most of the phones have PC's running off them.

I can see the phone rebooting in the log on the switch. But cannot find a reason for the reboot.

Does anyone have any ideas why this could be happening or know of any debugs that I can run that will show the cause of the reboot?



Re: Phones rebooting on hang up

what CCM version?

do u have SIP or SCCP phones?

New Member

Re: Phones rebooting on hang up

Using CCM version 4.1(3)sr5b

SCCP phones


Re: Phones rebooting on hang up


Check the Microsoft Windows 2000 Event Viewer for ur phones resets.

You will see one warning and one error message for each phone that resets. This indicates that the phone cannot keep its TCP connection to the Cisco CallManager alive, so the Cisco CallManager resets the connection. This may occur because

1: a phone was turned off or

2: a problem may exist in the network.

If this is an intermittent problem, you may find it useful to use Microsoft Performance Monitor to record phone registrations.

Here is a link to assist in determining error messages seen in the Event Viewer on the server:

System error messages for Cisco CallManager: (Look for “Device type” and “Reason




New Member

Re: Phones rebooting on hang up

This is a copy of the error in the event log that the customer has sent to me. From looking at the above link I think that this is a device initiated reset.

Can someone please either confirm this with me or correct me.

Error: DeviceUnregistered - Device unregistered.

Device name.: SEP00170E010735

Device IP address.:

Device type. [Optional]: 115

Device description [Optional].: xxx-7941-1706

Reason Code [Optional].: 8

App ID: Cisco CallManager

Cluster ID: StandAloneCluster

Node ID:

Explanation: A device that has previously registered with Cisco CallManager has unregistered. This event may be issued as part of normal unregistration event or due to some other reason such as loss of keepalives.

Recommended Action: No action is required if unregistration of this device was expected..

Can anyone give me a reason why the phones are resetting themselves when the handset is hung up??