Troubleshooting guide

The BlackDiamond Systems
Advanced System Diagnostics and Troubleshooting Guide 17
The BlackDiamond Backplane
The BlackDiamond backplane is a passive backplane, meaning that all the active components such as
CPUs, ASICs, and memory have been moved onto plug-in modules, such as the I/O modules and
MSMs.
Figure 2: BlackDiamond passive backplane architecture (BlackDiamond 6808 shown)
The BlackDiamond backplane provides inter-slot electrical connections for both network data traffic and
a separate control bus for switch fabric management. Data traffic is carried on four AUI links between
each MSM and each I/O slot on BlackDiamond
6804 and BlackDiamond 6808 systems, and on two AUI
links between each MSM and each I/O slot on BlackDiamond
6816 systems. Device management occurs
on a 32-bit PCI bus connecting MSMs and I/O modules. The number of backplane slots for I/O
modules and MSMs determines the BlackDiamond system type (6804, 6808, 6816).
The chief advantages of a passive backplane are:
• The absence of active components yields a much lower possibility of backplane failure.
• You can remove and replace system modules faster, making upgrades and repairs easier, faster, and
cheaper.
NOTE
One disadvantage of a passive backplane is that a problem on one switch module might cause other
switch modules to fail. More information on this possibility is covered in later chapters of this guide.
Switch
Module
64 Gbps
Switch
Fabric
Eight Load-Shared
Gigabit Links
Fault-Tolerant
Switch Fabric
and System
Management
A
1
2
3
8
B
64 Gbps
Switch
Fabric
Switch
Module
Switch
Module
Switch
Module
DN_001
A