Page380 of 544 NT8D14Universal Trunk Card
553-3011-100 Standard14.00 January 2002
Signaling and control
The signaling and control portion of the Universal Trunk Card works with the
CPU to operate the car d hardware. The ca rd receives mess ages from the CPU
over a signaling channel in the DS-30X loop and returns status information to
the CPU over the same channel. The signaling and control portion of the card
provides the means for analog loop terminations to establish, supervise, and
take down call connections.
Signaling interface
All trunk signaling messages are three bytes long. The messages are
transmitted in channel zero of the DS-30X in A10 format.
Configuration information for the Universal Trunk Card is downloaded from
the CPU at power-up or by command from maintenance programs. Eleven
configuration messages are sent. Three messages are sent to the card to
configure the make/break ratio and A-Law or ยต-Law operation. One message
is sent to each unit to configure the trunk characteristics.