There are three types of shared lines:
SIP: basic shared line with limited features (supports call forking but does not have LED activity and lines are not linked. This type of shared line is available in normal SIP mode).
SIP_BLA line type: server-enhanced Sylantro Bridged Line Appearance line type.
SIP_SCA line type: server-enhanced Broadworks Shared Call Appearance line type.
BLA and SCA line types allow calls and lines to be shared by multiple users. A SIP server provides support for call presentation to multiple phones, call state notifications, and access control. These two line types require the set to be in SIP Enhanced mode.
The SIP Enhanced mode shared lines are shared among users but only the user who initiates activity on the line has full control over it. For example, if a shared line is busy (other than on Hold), and secondary share users press their corresponding line button, the shared line will not change state. If the shared line is Ringing, or on Hold, any share user who presses the corresponding line button will change the state of that call and get connected to the calling/held party. An exception to this scenario occurs when the server is configured to allow line seizure by multiple lines. (Mitel SIP phones support multi-call server programming.)
Requirements for making calls and picking up held calls from shared lines are the same as normal (non-shared) lines.
For information about programming shared lines, see Programming Shared Lines.