Operational Features
5-173
41-001343-02 REV05 – 07.2014
Bridged Line Appearance (BLA)
A SIP bridge line appearance (BLA) on the IP phones allows multiple devices to share a single directory address (DA).
For example, people working at a technical support department could be located in different places. If their desktop
phones are configured for BLA DA, when customer calls come in, all the phones with the BLA DA would ring but the call
can only be answered by one of them.
Once the call is answered, the rest of the phones reflect the status of the call. If the call was put on "hold" by the original
recipient, any one from the group can pick up 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 outgoing call on the BLA DA. All phones reflect the usage of the BLA DA. If the call is put 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 be associated with different line appearances.
Every BLA DA is independent from 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 in draft-anil-sipping-bla-02.tx
t
to present
the incoming call to or place an outgoing call on the specified line appearance instance. The parameter is carried in
"Alert-Info" header field over the request-URI (INVITE e.g.) or in the 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 IP phones using the Aastra Web UI or the config-
uration files.
The following table shows the number of lines that can be set to BLA for each model phone.
Configuring BLA
You can configure BLA on a global or per-line basis using the configuration files or the Aastra Web UI.
Note:
This feature is dependent on the IP telephony system to which the IP phone is registered and according to draft-anil-
sipping-bla-02.txt.
IP Phone Model
Possible # of BLA Lines
9143i
9
9480i
9
9480i CT
9
6730i
6
6731i
6
6735i
9
6737i 9
6739i
9
6753i
9
6755i
9
6757i
9
6757i CT
9
6863i
2
6865i
9
6867i 9