Getting Cisco phones working with asterisk may seem like a daunting procedure; getting SIP firmware installed on the phone, loading up the the firmware files in the tftp server, fearing that you will somehow brick the phone by an incomplete firmware upload…But I am here to reassure you that once you understand how Cisco phones update themselves, the fear and trepidation will subside. They just need a tftp server to update its firmware and it doesnt even have to be located on the asterisk/phone system itself. But what is essential in upgrading these phones is a DHCP server with option 150 enabled – an option to auto-provision the tftp server ip address when the DHCP server hands out the regular ip address to the phone.
Once the bootloader is upgraded, all passwords and networking information on the phone will be wiped out.
The phone will then wipe the flash and load whatever firmware is specified in the tftpd32 directory – if the phone just keeps downloading the term.defaults file constantly, just do an incremental upgrade to the firmware version that you want).
This will clear all settings on the phone and set it to defaults.
We are going to use a windows based machine and load tftp/dhcp software on it which will make our windows machine a server for our phones. Go here to download the tftp/dhcp server – Download and install version 3.23 ( a.
Below are instructions to upgrade/convert any Cisco 7940, 7941, 7960, 7961, 7970, 7971, 7942, 7962, 7945, 7965 IP phone to any firmware you want from the Cisco web site (SIP/SCCP), and to recover any cisco phone which may have screwed up somehow while upgrading firmware (like if you get the protocol application invalid message). Goto and create a login if you do not already have one.Its not uncommon for one phone to take up to 4-5 minutes to complete the entire process.Thats all there is to it, and now that the phone has a good universal application bootloader, you will have no trouble switching between SCCP and SIP by just pointing the phone to the appropriate directory.So the best thing to do is to upgrade your SCCP phone with a newer SCCP load before switching over to SIP.If you have a very old version of SCCP, you will find that you cannot immediately upgrade to this version.
The phone should find that it needs to upgrade itself until you stop editing the file with new firmware information. After the phone gets to SCCP version 8.0.9, all you have to do is just download the version of SIP firmware you want, and then extract it into a seperate directory.