BusinessPhone Communication Platform 4.0
Maintenance Instruction ASB 150 02 > Detailed Information On Boards

## Considerations for BTU boards

All registers on the board are marked as busy. So these registers cannot be seized any longer. The system tests the registers on the board to be shut down on their function (only for traffic or only for voice or both). If one or both register types (traffic or voice) are no longer available within the system because the board is going to be shut down and was the only one or last one with this register type on then the system responds with blocked function and lack of resources. These actions do not affect an active call but background music or music-on-hold may be changed to silence. After a call is finished the individual(s) are blocked automatically.

Check that the S/T switch settings are the same on the new BTU-B board as on the BTU-B board that was removed from the system. If a BTU-B is shut down, all data-calls (via the S-interface) are terminated too. This applies especially for automated calls.

Calls to a directory number belonging to an extension (also operator) located on a board which is in shut down state are rejected or diverted. While a board is removed from the system (the connectors from the board front are removed) the Power Failure Circuit (PFC) is disabled.

##### Changing music channels

If a BTU-* board is hot swapped with one or more connected music sources, all extensions and operators currently connected to one of these music sources (background music or music-on-hold) are switched to silence channels.

#### Insertion of a BTU board

When inserting a new board in a previously vacant slot there are no directory numbers assigned to the individuals after the board has been started. Directory number are to be assigned by RASC later on.

Revision: E © Ericsson Enterprise 2003