I have recently encountered problem with Cisco IP Phones. For some reason new phones just freeze at 0% of downloading while updating firmware. After a 20 or so minutes of freezing the phone turend on display, but all the buttons were disabled.

Device Configuration XML File. The XML file SEPAAAABBBBCCCC.cnf.xml (where AAAABBBBCCCC is the MAC address of the IP phone) contains the call agent IP address and port, firmware, locale, directory URL, and many other pieces of information. This file is present when the IP phone has been added to the configuration. Enterprise Gsync Download. Upgrade any Cisco Phone FIrmware without Cisco Communications Manager (CUCM). Use your own TFTP.

For variety of reasons it seemed like WAN troubles, so I decided to upgrade firmware on my CP-6941 phones without Call Manager. First of all, I needed TFTP Server for Windows. Fortunately, I have found installed old one Cisco TFTP Server.

It has been discontinued and is no longer supported by Cisco Systems, but still works:) Anyway, there is some alternatives, such as, which is a free, opensource IPv6 ready application which includes DHCP, TFTP, DNS, SNTP and Syslog servers as well as a TFTP client. Next step was to create config file for the Phone to catch-up right firmware. I have made simple XMLDefault.cnf.xml to use one file for all phones.

1 2 3 SCCP69xx.9-3-1-3 Then I just copied XMLDefault.cnf.xml and unzipped firmware package files: SCCP69xx.9-3-1-3.loads and SCCP69xx.9-3-1-3.zz.sgn to TFTP root. In my case firmware with correct version was recieved from our Communication Manager admins, but it seems like it is possible to obtain it from Cisco software download section. Finally, I’ve changed DHCP option 66 to point to my local TFTP server address and powered-on phones. Etherything have worked like a charm. After upgrade, I switched option DHCP settings back to primary TFTP server and reboot devices.

So, I have manually updated Cisco’s IP phones to correct firmware and they were able to connect server. Posted by Alex Matashkin 01 July 2013.