Do you know how the Slots DistributionHuawei on Huawei OptiX OSN 6800 Subrack

Subracks are the basic working units of Huawei OptiX OSN 6800. The subrack of the OptiX OSN 6800 has an independent power supply.

1. Indicator and interface area
2. Board area
3. Fiber cabling area
4. Fan tray assembly
5. Air filter
6. Fiber spool
7. Mounting ear

• Indicators: indicate the running status and alarm status of the subrack.
• Board area: All service boards are installed in this area. 21 slots are available.
• Fiber cabling area: Fiber jumpers from the ports on the front panel of each board are routed to the fiber cabling area before being routed on a side of the open rack. The mechanical VOA is also installed in this area.
• Fan tray assembly: Fan tray assembly contains ten fans that provide ventilation and heat dissipation for the subrack.
• Air filter: The air filter protects the subrack from dust in the air and requires periodic cleaning.
• Fiber spool: Rotable fiber spools are on two sides of the subrack. Extra fibers are coiled in the fiber spool on the open rack side before being routed to another subrack.
• Mounting ears: The mounting ears attach the subrack in the cabinet.
• Interface area: The interface area provides functional interfaces, such as management interface, inter-subrack communication interface, alarm output and cascading interface, alarm input and output interface. It is behind the subrack indicator panel.

Slot Description

The board area of the subrack has 21 slots, labeled IU1 to IU21 from left to right.

• houses service boards and supports service cross-connections.
• IU15 and IU16 are also available for the STG. IU9 IU10 is the cross-connect slots.
• Pair slots refer to a pair of slots whose resident boards' overhead can be processed by the buses on the backplanes. OptiX OSN 6800 supports pair slots.
  • At a site where OSC signals pass through, two OSC boards must be configured in paired slots.
  • When line boards or OTU boards function as regeneration boards, ESC signals need to pass through the boards. In this scenario, the two line boards or OTU boards must be configured in paired slots.
  • Paired slots among slots IU1 to IU8 and IU11 to IU16 support distributed service grooming.

Generation and Detection of Alarms and Performance Events in the SDH Higher Order Signal Flow

The principle for locating fault is "line first, then tributary; higher order first, then lower
order".
Therefore, this section focuses only on the alarms and performance events generated between
the SDH interface and the cross-connect unit like Huawei GXCSA during maintenance. This section describes the signal flow and the procedure for handling each overhead byte by each module.

Alarm signals generated between the SDH interface and the cross-connect unit

Based on the positions of the various overhead byte processing in the STM-64, STM-16, STM-4, STM-1 frame, the overhead
bytes are classified into four modules:
Regenerator section overheads
Multiplex section overheads
Higher order path overheads
Lower order path overheads
If a fault occurs in the first two modules, it affects all the higher order paths. If a fault occurs in
the overhead bytes of a higher order path, however, it affects only this higher order path and its
lower order paths.
The following sections describe the signal flow and the processing of each overhead byte.

Downlink Signal Flow
In the higher order downstream signal flow, overhead bytes are extracted and terminated.
Frame Synchronizer and Regenerator Section Overhead Processor

Uplink Signal Flow
The overhead bytes are extracted and then terminated in the downlink signal flow of the higher
order path. Overhead bytes are generated and alarm signals are returned to the opposite NE in
the uplink signal flow of the higher order path.

Generation and Detection of Alarms and Performance Events in the SDH Higher Order Signal Flow

The principle for locating fault is "line first, then tributary; higher order first, then lower
order".
Therefore, this section focuses only on the alarms and performance events generated between
Huawei SDH interface and the cross-connect unit during maintenance. This section describes the
signal flow and the procedure for handling each overhead byte by each module.
Alarm signals generated between the SDH interface and Huawei cross-connect unit

Based on the positions of the various overhead byte processing in the STM-N (Huawei STM-64, STM-16, STM-4) frame, the overhead
bytes are classified into four modules:

• Regenerator section overheads
• Multiplex section overheads
• Higher order path overheads
• Lower order path overheads

If a fault occurs in the first two modules, it affects all the higher order paths. If a fault occurs in
the overhead bytes of a higher order path, however, it affects only this higher order path and its
lower order paths.
The following sections describe the signal flow and the processing of each overhead byte.
Downlink Signal Flow
In the higher order downstream signal flow, overhead bytes are extracted and terminated.
Frame Synchronizer and Regenerator Section Overhead Processor
Multiplex Section Overhead Processor
Pointer Processor and Higher Order Path Overhead Processor
Uplink Signal Flow
The overhead bytes are extracted and then terminated in the downlink signal flow of the higher
order path. Overhead bytes are generated and alarm signals are returned to the opposite NE in

the uplink signal flow of the higher order path.