Background
In order to debug problems with Cisco Unified IP Phones 6900 series it may be necessary to collect the phone console logs from the phone itself. This document covers how to collect debugs to troubleshoot issues with the Cisco 6900 Series IP Phones. In troubleshooting most issues, it is also extremely important to gather a packet capture from the IP Phone as well. The packet capture procedure is covered in this document.
Prerequisites
In order to gather debugs from the 6900 series IP Phones, the following is required:
- Access to the Cisco Unified Communications Manager (CUCM) Administration interface
- A secure shell client which supports logging
Enable Secure Shell Access
Enable Secure Shell Access on an individual phone
Debugs are collected by use of a secure shell session to the IP Phone. To enable debugs on a particular phone, login to the CUCM Administration interface, navigate to Device->Phone, and locate the phone in question.

Enable Secure Shell access on a group of phones
If the issue is intermittent and not isolated to any particular phone, it may be required to enable Secure Shell access on a group of phones as defined by a Common Phone Profile. In this case navigate to Device->Device Settings->Common Phone Profile, and locate the common phone profile assigned to the desired subset of devices.

Specify a Secure Shell Username and Password
Either on the phone configuration page, or on the Common Phone Profile Configuration, locate the "Secure Shell Information" section.

Specify a username and password to be used for Secure Shell access.
Enable Secure Shell Access
Again, either on the phone configuration or on the Common Phone Profile Configuration, locate the "SSH Access" setting and set it to "Enabled."

Reset the phones
The phones must be reset in order to take the updated configuration file.

Gathering the debugs
At this stage, Secure Shell access should be enabled on the phone and it is now possible to login to view and collect the debugs.
Login using SSH
Launch the Secure Shell client and connect to the IP address of the phone of the phone using SSHv2 on TCP port 22.

Login using the credentials specified in the previous step Specify a Secure Shell Username and Password.
Access admin prompt through VxWorks login
A VxWorks prompt will be provided. The default credentials are
username/password : admin/<empty>
Enable Required Debugs
Cisco TAC may require certain specific debugs to be enabled.

Enable logging on SSH Client
Each SSH Client has a different method for logging the session, this screenshot illustrates how to enable logging of printable output on a putty session.

Reproduce the problem symptom
Once the required debugs are enabled and logging is enabled on the SSH Client, take action if needed to reproduce the problem symptom or condition.
Save the debugs
Stop logging on the SSH Client and copy the previously created file off for analysis.