It would be really great to be able to assign a BLF key to an Extension rather than a handset. We have a few users who have 2 handsets (home and office) and would love a way to know if the user/extension was busy instead of just one of the handset without using extra PFKs.

+1
I agree. Would it matter if the BLF was assigned to and Extension vs a User? Would that make any difference? I guess they are the same thing.
Many of our users will have AllWorx IP sets in the office, and may also have a Generic SIP client on their PC or iPhone. I don't think BLF's work for Generic SIP clients, but I haven't tested this fully yet. Would want those included.
I don't care what an end users is on the phone with, I just want to know if they are on the phone.

justingoldberg wrote:blfs do work with sip.

Can you clarify? Or perhaps my explanation wasn't clear.
I go to modify my PFK's, select BLF, but I can't then select a Generic SIP handset - only Allworx IP sets.
I can do a Speed Dial PFK to a users extension - but that doesn't tell me if they are on the phone.
In Call Assistant when a user is on the phone on a Generic SIP device it doesn't turn Red like it does for an Allworx IP set.

Sorry, I was thinking about BLFs for analog handsets, these are supported.