When an application is logged on to an IP Office system but does not stay in the same local subnet, IP Office sends BLF update notification messages directly to the PC that the application is running on. This is a Unicast message. Each IP Office only supports BLF update notifications for 10 remote applications, provided on a first come first served basis. When the system starts, the first 10 connections from a different subnet receives BLF update notifications. The system does not provide BLF update notifications to subsequent connections. All other features operate normally.

An example of user state information updates is shown below: