Hope somebody out there can help we have a 2820 IPPX phone system with SIP Yealink handsets and need to connect our SPA112 as if it is an extension to make an analogue/DTMF door phone work on the system as an extension?  Has anybody ever done this as...

Has anybody ever configured a SPA112 to a Draytek 2820IPPX.I want to use a SPA112 to activate a DTMF door entry system through a Draytek 2820IPPX telephone system using a SIP / EXT on the phone systemSo any tips or if you have a copy of a configurati...