Operational Features5-144 41-001160-00, Release 2.1, Rev 04IP Phone Administrator GuideOperational IP Phone Features Bridged Line Appearance (BLA) (55i, 57i, 57i CT only)A SIP bridge line appearance (BLA) on the IP phones allows multiple devices toshare a single directory address (DA).For example, people working at a technical support department could be locatedin different places. If their desktop phones are configured for BLA DA, whencustomer calls come in, all the phones with the BLA DA would ring but the callcan only be answered by one of them.Once the call is answered, the rest of the phones reflect the status of the call. If thecall was put on "hold" by the original recipient, any one from the group can pickup the call.You can apply BLA on the IP phones as follows:• As a single BLA group - One BLA DA is shared among multiple phones.Only one phone at a time can pick up an incoming call or initiate an outgoingcall on the BLA DA. All phones reflect the usage of the BLA DA. If the call isput on "hold", any one from the group can pick up the "held" call.• As a multiple BLA group - On one single phone, multiple BLA DA can beassociated with different line appearances. Every BLA DA is independentfrom each other and follows the same rules as "a single BLA group".• As multiple instances of a BLA DA - A "x-line-id" parameter was defined indraft-anil-sipping-bla-02.txt to present the incoming call to or place anoutgoing call on the specified line appearance instance. The parameter iscarried in "Alert-Info" header field over the request-URI (INVITE e.g.) or inthe NOTIFY messages to report the status of a dialog.BLA DA can be configured on a global basis or on a per-line basis on the IPphones using the Aastra Web UI or the configuration files.Notes:1. This feature is dependent on the IP telephony system to which the IPphone is registered and according to draft-anil-sipping-bla-02.txt.2. Interactive Intelligence and Sylantro servers support the single BLAgroup with single line appearance feature only.
