Nortel DMS-10 Series Installation, Operation And Maintenance Manual page 433

The automatic operation of the BMC means that little user intervention is
required. To provide greater understanding of operation, the transfer of data
from the Switching System, the translation for intermediate storage, the
polling of data to the HOC, and maintenance communications are described
in this section.
Offload of data from the Switching System
The following section details the information related to the offload of data
from the Switching System to the BMC.
Acquisition and Storage of Data
The transfer of call record data from the Switching System is through the
Switching System's active MTP to the BMC through Switching System-
specific Interface Box(es). Call record data is organized into blocks. These
blocks can be from 9 to 2048 bytes long. The length of the block is
dependent on the site data previously entered into the BMC memory. If call
record data is less than the specified number of bytes, the remainder of the
block is filled with hexadecimal AAs. Refer to the System Description
section. Data is passed from the MTP to the BMC through Switching System
specific Interface Box(es).
Interface Boxes
Interface Boxes provide the electrical and physical connection between the
Switching System MTP and the TEC/DSI PCAs of the BMC. The Interface
Boxes match the electrical characteristics of the physical layer protocol of the
Switching System with the physical layer protocol of the BMC. The exact
nature of the interface depends on the particular Switching System type.
Interface Boxes are discussed in greater detail in the applicable Switching
System Specific Data section. The Switching System characteristics are
matched to the characteristics of the TEC/DSI PCAs.
TEC/DSI PCAs
The TEC/DSI PCAs are controlled by an on-board microprocessor and
firmware instruction set. Each of these PCAs emulates the control signals and
protocol requirements of an MTU. During data transfer, the active tape port
sends a port select signal to the BMC. This signal is applied to both TEC/DSI
PCAs, one in the active processor and one in the standby processor. This
signal alerts the BMC as to which port is to be used and to treat all data from
the other port as test data. The TEC/DSI software responds to the commands
that are normally sent to the tape drives, and provides the status, control, and
strobe signals normally expected. The TEC/DSI PCAs form part of the
physical layer and most of the link layer protocols for communication
between the BMC and the Switching System. The TEC/DSI PCAs accept
data from the MTP and places it in RAM for processing by the active
processor.
BMC II BISYNC Operation, Administration, and Maintenance Guide BMCB001 and up
Section 060-INDP-510 System Operation Guide 5-3