The Blackdiamond Backplane - Extreme Networks BlackDiamond 6804 Troubleshooting Manual

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)
Switch
1
Module
Switch
2
Module
Switch
3
Module
Switch
8
Module
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.
Advanced System Diagnostics and Troubleshooting Guide
Eight Load-Shared
Gigabit Links
64 Gbps
Switch
Fabric
A
Fault-Tolerant
Switch Fabric
and System
Management
B
64 Gbps
Switch
Fabric
DN_001A
The BlackDiamond Systems
17