RJ9 Electronic Hook Switch port is used for Headset  connectivity with IP Phone set.

BLF stands for Busy Lamp Field (BLF) & it has three major functions:   It can be used for Speed

Line Keys are used for call forward to another extension and also multi conference between several Extension users.

Simply, a SIP Trunk is an IPTSP number where all calls are being routed through Internet.   SIP Trunk can

A SIP account is a set of credentials that allows users IP Phone to make voice and video calls over