Yealink SIP-T2 SERIES Administrator's Manual page 554

Administrator's Guide for SIP-T2 Series/T19(P) E2/T4 Series/CP860 IP Phones
3. (Optional.) Enter the string that will appear on the LCD screen in the Label field.
4. Click Confirm to accept the change.
To configure an LDAP key via phone user interface:
1. Press Menu->Features->DSS Keys.
2. Select the desired DSS key.
3. Press
4. Press
5. (Optional.) Enter the string that will appear on the LCD screen in the Label field.
6. Press the Save soft key to accept the change.
BLF is used to monitor a specific user for status changes on IP phones. For example, you
can configure a BLF key on a supervisor's phone to monitor the IP phone user status
(busy or idle). When the monitored user places a call, a busy indicator on the
supervisor's phone indicates that the user's phone is in use.
When the monitored user is idle, the supervisor can press the BLF key to dial out the
phone number. When the monitored user receives an incoming call, the supervisor can
press the BLF key to pick up the call directly. When the monitored user is in a call, the
supervisor can press the BLF key to interrupt and set up a conference call.
Note
BLF is not applicable to SIP-T19(P) E2 and CP860 IP phones.
BLF Subscription
IP phones support BLF using a SUBSCRIBE/NOTIFY mechanism as specified in
This feature depends on support from a SIP server.
When the IP phone is configured to monitor a specific user, it sends a SUBSCRIBE
message to the server. A NOTIFY message which includes XML in the message body is
sent to the IP phone to inform the current state of monitored user. Once status of the
monitored user is changed from idle to busy or vice versa, the IP phone is notified from
the server with a NOTIFY message. You can manually configure the period of the BLF
532
or , or the Switch soft key to select Key Event from the Type field.
or , or the Switch soft key to select LDAP from the Key Type field.
RFC 3265.