Extreme Networks ExtremeWare Version 7.8 Troubleshooting Manual page 51

Diagnostic tests are processed by the CPU. When invoked, each diagnostic tests looks for different
things (device problems, communication-path problems, etc.), and uses either the control bus or the
data bus, or—in some cases—both buses to perform the test.
For example,
test sends five different diagnostic packets across the control bus to each I/O module. From the I/O
module, the packets are looped back to the CPU across the control bus. The CPU inspects the packets
for loss or errors.
Figure 9: CPU health check path (BlackDiamond architecture)
Control Bus
Control Bus
I/O Module (G8Xi)
Figure 10 shows a simplified example of the backplane health check test. In the backplane health check,
the CPU uses the control bus to load test packets into the fabric of the MSM. The packets are then
transferred across the backplane from the MSM to the fabric on a given I/O module. The health check
packets are then returned to the CPU which processes the results.
Advanced System Diagnostics and Troubleshooting Guide
Figure 9 shows a simplified example of the CPU health check test. The CPU health check
AFQM
ASIC
(Quake)
SE
ASIC
(Twister)
(To all other slots)
Control Bus
AFQM
ASIC
(Quake)
SE
ASIC
(Twister)
Control Bus
Master MSM (MSM-A)
Diagnostic Test Functionality
NVRAM
CPLD
CPU
Subassembly
UART
PCMCIA
FLASH
SRAM
MGMT
Master MSM Daughter Card
CPU transmits test
packet to SE ASIC
on Control bus.
SE ASIC transmits
back to CPU on
Control bus.
DN_031A
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