Port Congestion - Cabletron Systems SmartCell 6A000 User Manual

Troubleshooting Congestion
Enter the
4.
show cacstats
mostly UBR?
•
If no, go back to step 4 and check next port.
•
If yes, continue.
5. Enter the
show porttrafficcongestion
•
If no, go back to step 4.
•
If yes, continue.
Reduce the UBR queue Max threshold by a small amount, then wait a few minutes.
6.
Enter the
7.
show portstats
increasing for this port, and quickly decreasing for all other ports?
•
If yes, proceed to the "Port Congestion" section.
•
If no, continue.
8. Is the number of cells being dropped by all other ports decreasing somewhat?
•
If no, go back to step 7.
•
If yes, continue.
Enter the
9.
set cacparams
conservative policy (
moderate
Go back to step 4 until all ports have been checked.
10.
5.3.3

Port Congestion

Enter the
1.
show portstats
unknown VCs dropped. Is the difference for cells dropped equal to the difference for VCs
dropped?
•
If yes, the switch is improperly set up. Check the switch configuration.
•
If no, this indicates port congestion. Continue.
Enter the
2.
show cacstats
Service on this port.
3. For each class of service, enter the
to the value recommended in the "Class of Service Queue Allocation Guidelines" section.
4. Have you performed step 3 for every class of service for this port?
•
If no, go to step 3.
•
If yes, continue.
5. Enter the
set cacparams
conservative policy (
moderate
Check VC statistics for this port using either the
6.
whichever is appropriate.
If the port belongs to the high virtual channel link (VCL), read the forward stats. If the port belongs
7.
to the low VCL, read the backward stats. If the port belongs to both high and low VCLs, read both
stats.
5-4 SmartCell 6A000 User Guide
command for each port. Is the allocated bandwidth small and is the traffic
command. Is the UBR queue Max threshold large?
command, and take the default of
command and set call admission control for this port to a more
or ).
conservative
command a few times, noting the value for cells dropped and
command for this port. Note the bandwidth allocated for each Class of
set porttrafficcongestion
command for this port. Set call admission control for this port to a more
or ).
conservative
show pvc /d
. Is the number of cells dropped
all
command. Set the Max threshold
or the command,
show svc /d
Troubleshooting