Busy lamp field (BLF) is a feature for many SIP desk phones that shows the line condition for other users on the same PBX (domain). The users are displayed as buttons on the device, depending on the number of feature buttons available on the particular model of phone (see chart below).
To use BLF, you must enable it for your PBX (organization) on the "account" tab of the admin portal. If your account has more than one PBX (organization), please ensure the correct one is selected in the "Active PBX" drop down.
Note: BLF is included for OnSIP customers on the Per Seat Metered Plan, though your OnSIP admin must still enable BLF for your PBX (organization) to use it. For customers on the Pay As You Go Plan, please refer to our pricing page on www.onsip.com.
You will configure BLF individually for each phone via the OnSIP provisioning server. An instruction guide can be found in the knowledgebase article for setting up phones.
Phones supported at the moment:
- Polycom Soundpoint IP 450/550/560/650/670
- Polycom VVX 300/VVX310/VVX400/VVX410/500/600
- Panasonic KX-UT 133/136B/248B/670/UTG200B/UTG300B
- Cisco/Linksys SPA941/942/962/501G/504G/508G/509G/525G/525G2
- Yealink T20P/T21P/T22P, T23P/T26/T28/T32/T38/T41P/T42G/T48G
- Grandstream GXP2124/2100/2110/2120/2130/2140/2160/ GXV3240/GXV3275/UTG200B/UTG300B
Updated August 2015
Technical Notes Updated October 2017 :
* "Ringing" state has a five minutes timeout.
* "Committed" (On a call) has a one hour timeout.
* "Terminated" status has a 12 hour timeout. Timeouts do not publish a status alert.