Network Interface (Trunk) Cards 4-13
Broadband Network Interface Cards, BNI-155
The Line Interface Unit (LIU) performs the following egress functions:
• Inserts the appropriate framing into the outgoing bit stream.
• Inserts any alarm codes for transmission to the far end.
• Provides optional cell scrambling, HEC generation, and idle cell insertion.
• Provides a small FIFO buffer outing cells.
• Provides electrical to optical conversion.
Figure 4-6 Simplified BNI-155 Block Diagram
Front Panel Indicators
The BNI-155 front panel (see Figure 4-7) has a three-section, multicolored “card” LED to indicate
the card status. The card status LED is color-coded as indicated in Table 4-4. A three-section
multicolored “port” LED indicates the status of the two ports on the BNI-155. Types of failures are
indicated by various combinations of the card status indicators as indicated in Table 4-5.
StrataBus
Serial
Interface
Unit
(SIU)
CommBus
Iinterface
Control/Admin
processor
Network
address table
CIE port 1
QSE port 1
CIE port 2
QSE port 2
LIU port 1
LIU port 2
LIU = Line Interface Unit
CIE = Cell Input Engine
QSE = Queue Service Engine
Egress
(from BCC
switching
matrix)
Ingress
(to BCC
switching
matrix)
H8229
