Hello, i have an XR2000 unit with the latest Elastix on plus a Portech unit that connects me to the gsm network and a Yealink T-28. I have set them all pretty fine, i can make and receive calls and now i want to monitor this trunk through a BLF side key. I have added the next three line in extensions_custom.conf exten => gsm1,hint,SIP/trunkname exten => gsm1,1,Dial(DAHDI/trunkname) exten => gsm1,n,Hangup And the settings for the DSS key are Type: BLF and Extension: gsm1. I don't know if i need anything on the Portech. Any suggestions are welcomed.