A Bridged Line Appearance is used on either an MGCP or SIP phone when there is a need to have an instance of another line other than that of the current phone. For instance, on a standard Cisco 7960 MGCP phone, the first two line buttons can be assigned the extension on that phone, and the remaining 4 buttons can be assigned BLA's that correspond to the 4 main lines coming into the office. Another example would be to assign a virtual extension to the phone, allowing the user to see if the person at that extension is using their phone, or to allow direct dialing to that extension with the press of a button. It should be noted that an MGCP BLA cannot be assigned to a SIP phone, and a SIP BLA cannot be assigned to an MGCP phone.
When is a BLA used?
