asterisk-moh-opsound-gsm 2.03-1.1 (amd64 binary) in ubuntu lunar

 Asterisk is an Open Source PBX and telephony toolkit. It is, in a
 sense, middleware between Internet and telephony channels on the bottom,
 and Internet and telephony applications at the top.
 .
 Asterisk includes a set of standard sound files in various formats. This
 package contains several "on-hold" music files in raw gsm-fr format
 (Compressed. Takes relatively little space. playable with sox).