Mitel 6800 Series, Administrator'S Manual, Page: 477 / 1113

Operational Features
5-214
sip line1 mode: 3
sip line1 user name:4085582868
sip line1 display name: Alice
sip line1 screen name: Alice
P-PREFERRED IDENTITY HEADER FOR BLA ACCOUNTS
The IP Phones support the BLA specification, draft-anil-sipping-bla-02, which states that the
P-Preferrred-Identity header (RFC3325) gets added to the INVITE message to indicate the
Caller-ID that is used for the call.
BLA SUPPORT FOR MESSAGE WAITING INDICATOR (MWI)
The IP Phones have an option for a Busy Line Appearance (BLA) configured line to send a
SUBSCRIBE SIP message for a Message Waiting Indicator (MWI).
You can configure this feature using the configuration files or the Mitel Web UI.
Limitations
The following are limitations of the BLA Support for MWI feature:
• The phone shows MWI for the first matching identity if more than one line with different
user names has the same BLA account.
• If a normal line has the same user name as the BLA user of another line, the phone shows
MWI only for the normal line.
Note:
The P-Preferred-Identity for BLA accounts is also sent for hold/unhold messages.
Notes:
1.
If you change the setting on this parameter, you must reboot the phone for it to take
affect.
2.
Both the “
sip explicit mwi subscription
” and “
sip mwi for bla account
” parameters
must be enabled in order for the MWI subscription for BLA to occur.
3.
The MWI re-subscription for the BLA account uses the value set for the "
sip explicit
mwi subscription period
" parameter to re-subscribe.
4.
Whether or not the "
sip mwi for bla account
" parameter is enabled, the priority
for displaying MWI does not change.