An Avaya telephone is an IP phone used to make calls over an IP network, usually the Internet. The Avaya phone, as all other IP phones, uses the Voice over IP technology to make calls over the Internet. While ordinary telephones use a PSTN system, IP phones use an Internet Protocol, or an IP system. IP phones can either look like ordinary telephones or cordless telephones, or they can be software based. The Avaya telephone is a one of the IP phone models manufactured by Avaya Inc, one of the largest telecommunication companies in the Unites States.
Inspect the hardware of your Avaya phone first. Look at the speaker and the microphone. If they appear to be damaged or broken, replace those parts with new ones.
Look at the Avaya's telephone's display. Depending on your specific Avaya model, it can be a small and simple display or a large, multi-color touch display. If the display is cracked or damaged, it may be necessary to buy a new phone. However, if the only thing broken is the glass of the display, it may be possible to replace it in an authorized service.
Check the battery of your Avaya phone, if you have a handset cordless model. Check the battery inside the base station as well. Remember that both components of the Avaya telephone have to work properly in order for the phone to be functional. If needed, replace the batteries and then check if your IP phone is working.
Press the "Mute" key on your Avaya phone and then the numbers "8439#." At this point, you will see a list of different features, starting from the telephone's IP address, the server's DHCP address to the call manager address. For example, if the number following the DHCP is much larger than 15, there is a problem with the DHCP server. In that case, simply continue detecting the problem as with any other device that uses a network or Internet.
Check if there is a problem with accessing the TFTP server. Make sure that the TFTP server is running. Then have someone on a PC access the TFTP and confirm that the files are reachable. Remove any file and directory permissions that disable the TFTP connection.
When troubleshooting your Avaya telephone, take the opportunity to set various features, such as caller ID, call park, call transfer, and different applications, such as weather report and live news.