To further complicate this task, the information available on configuring the newer and more user-preferred devices (touch screens, color backlit display, etc.) is extremely sparse and largely unconfirmed.After heading up the deployment of 3 small Asterisk based PBX deployments, all of which were to make use of various different Cisco IP Phone models; a great deal of information about these phones has been collected.I chose to install it on the same server as Asterisk for 1) simplicity, and 2) to ensure the system was self-contained.
The first step is to connect to the Asterisk server via SSH as root.Once connected to the server, install the TFTP software: The TFTP server is an ‘xinet’ application and therefore xinetd will also need to be installed if it is not already. By default, the folder used by the TFTP server is /tftpboot. Once installed run the following commands to ensure that both xinetd and the TFTP server are initialized on server startup: NOTE: The TFTP server for the Cisco IP Phones can be located on a different server if desired.In addition to the three supported protocols, there are also several different versions of each firmware.In most cases it is recommended that the most recent version of firmware for the needed protocol be used.Superb call quality, a large easy-to-read display screen and user-friendly button layouts/designs make the Cisco phone models of old and late some of the best hardware available for IP-based phone systems.
However, for all their outstanding advantages, configuring these phones to work with a non-Cisco managed Vo IP network can be a bit of a chore.Cisco IP Phones using SIP firmware will use DHCP-option (port) 69 for connecting to the TFTP server and obtaining its configuration.Phones loaded with firmware that makes use of a Cisco Call Manager application (usually SCCP or MGCP) may look for configuration information on port 150 (the TFTP port used by the CCM).The Asterisk NOW install is a complete installation package available for free that runs off of the Cent OS Linux distribution.It comes pre-configured with a working asterisk installation (with all major / common libraries installed) and the Free PBX GUI for administering the Asterisk server via a web interface.Phone currently with SCCP 8.x: if unable to upgrade to SIP 8.x directly, loading SIP 7.x or SCCP 7.x before upgrading to SIP 8.x).