The following is from a cheat sheet someone gave me. I use Pumkin from Klever for TFTP it is a free download.
File name must be music.mtd
1. Enter the configuration Mode (Hold, Transfer, *, #).
2. Enter the maintenance Mode (Hold, #, *).
3. Select 2 for Download Address. Enter the IP address of the FTP/TFTP server.
4. Select OK.
5. Select 5 for Download.
6. Select 5 for Music.
7. Select FTP or TFTP based on the type of file server you are using.
8. During transfer you will see Downloading…
9. Once complete you will see Download Complete in the Dterm display.
10. Select Exit.
Settings should be as follows…
a. Sample rate should be 8000Hz
b. The channel set to Mono.
c. Resolution should be at 8bit.
d. Select Ok
• Go to File type and select Save As…
a. Change Save as type: to A/mu-Law Wave (*.wav)
b. In File name: enter music.mdt
c. Save the file to a location that can be accessed by the FTP/TFTP serv