Troubleshooting Congestion | Troubleshooting |
5.4.1Diagnosing Congestion
s• Enter the show portstats command, and take the default of (all).
¢• If cells are not being dropped on all ports, proceed to the “Port Congestion” section.
••If cells are being dropped on all ports, the indication is global congestion. Proceed to the “Global Congestion” section.
5.4.2Global Congestion
s• Is the total cell drop rate equal to the Unknown VC cell drop rate?
UIf yes, the switch is improperly set up. Check the switch configuration.
UIf no, this indicates global congestion. Continue.
¢• Set the porttrafficcongestion values to those recommended in the “QoS Queue Allocation Guidelines” section. Has the congestion subsided?
UIf yes, you are done.
UIf no, continue.
••Have you changed the EPD threshold?
UIf yes, replace it to the default setting. If congestion subsides, you are done.
UIf no, continue.
T• Enter the show cacinfo command for each port. Is the allocated bandwidth small and is the traffic mostly UBR?
UIf no, go back to step 4 and check next port.
UIf yes, continue.
Q• Enter the show porttrafficcongestion command. Is the UBR queue Max threshold large?
UIf no, go back to 4.
UIf yes, continue.
••Enter the show portstats command, and take the default of all. Is the number of cells dropped increasing for this port, and quickly decreasing for all other ports?
UIf yes, proceed to the “Port Congestion” section.
UIf no, continue.
G• Is the number of cells being dropped by all other ports decreasing somewhat?
UIf no, go back to step 6.
UIf yes, continue.
n• Enter the set caceqbwallocscheme command and set call admission control for this port to a more conservative policy (moderate or conservative).
s¥ Go back to step 4 until all ports have been checked.
