Sangoma Phones PJSIP Presence Module
Presence
Asterisk 12 and newer ship with a a module, res_pjsip_pidf_digium_body_supplement, that is used to pass enhanced Presence information from Asterisk into Sangoma phones. If you are using a Sangoma phone with DPMA, this module is necessary. If you are using a Sangoma phone with the FreePBX REST-ful Phone Apps, this module is necessary. If you are using Sangoma phones otherwise with Asterisk 12 or 13 or newer, there is no need to load this module into Asterisk; if you do so, your phone's line indicator icon will indicate an unknown presence state with a question mark.
For users outside of DPMA and/or the FreePBX REST-ful Phone Apps, this module may be prevented from loading in Asterisk by adding the following line to modules.con in the existing [modules] context, e.g.:
[modules]
...
noload => res_pjsip_pidf_digium_body_supplement.so
...