Cabletron Systems 6A000 manual Diagnosing Congestion, Global Congestion

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Troubleshooting Congestion

Troubleshooting

5.4.1Diagnosing Congestion

1.Enter the show portstats command, and take the default of (all).

2.If cells are not being dropped on all ports, proceed to the “Port Congestion” section.

3.If cells are being dropped on all ports, the indication is global congestion. Proceed to the “Global Congestion” section.

5.4.2Global Congestion

1.Is the total cell drop rate equal to the Unknown VC cell drop rate?

If yes, the switch is improperly set up. Check the switch configuration.

If no, this indicates global congestion. Continue.

2.Set the porttrafficcongestion values to those recommended in the “QoS Queue Allocation Guidelines” section. Has the congestion subsided?

If yes, you are done.

If no, continue.

3.Have you changed the EPD threshold?

If yes, replace it to the default setting. If congestion subsides, you are done.

If no, continue.

4.Enter the show cacinfo command for each port. Is the allocated bandwidth small and is the traffic mostly UBR?

If no, go back to step 4 and check next port.

If yes, continue.

5.Enter the show porttrafficcongestion command. Is the UBR queue Max threshold large?

If no, go back to 4.

If yes, continue.

6.Reduce the UBR queue Max threshold by a small amount, then wait a few minutes.

7.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?

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 6.

If yes, continue.

9.Enter the set caceqbwallocscheme command and set call admission control for this port to a more conservative policy (moderate or conservative).

10.Go back to step 4 until all ports have been checked.

5-4 SmartCell 6A000 User Guide

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Contents SmartCell 6A000 User Guide Ii SmartCell 6A000 User Guide FCC Class a Notice Declaration of Conformity Addendum Safety Information Class 1 Laser Transceivers Fiber Optic Protective Caps Regulatory Compliance Summary Safety Revision History Table of Contents Specifications Acronyms Index Xii SmartCell 6A000 User Guide List of Figures List of Figures Xiv SmartCell 6A000 User Guide List of Tables List of Tables Xvi SmartCell 6A000 User Guide Introduction Introduction SmartCell 6A000 User Guide Inspecting the Switch Switch Installation and SetupUnpacking the Switch Check Accessory Carton Contents6A-IOM-29-4 Face Plate Number Physical Specification 6A-IOM-21-46A-IOM-22-4 6A-IOM-29-4-IRInstalling the Switch 1 DS3 and E3 I/O Module ConfigurationInstalling the Switch Configuring the Switch Switch Installation and SetupConfiguring the Switch 6A000 console and network connections Using the Console Console CommandsSmartCell ZX # show portconfig a1 Console Time-out Creating an AliasAmbiguous Commands Console HelpSmartswitch ATM Administrator SmartCell ZX # ? add laneclientExterior Installation Steps MB RAMStarting SmartSwitch ATM Administrator the First Time User Name Access Level Default PasswordAccessing Online Help SmartSwitch ATM Administrator IP Over ATM and Lane Creating AN IP Over ATM VlanServer Is local Server Connection Established Creating AN Emulated LAN ATM Addressing for IP over ATMNo Lane server address is specified see note below Ilmi ELANs Across Multiple Switches Switch ClientsATM Addressing for LAN Emulation Elan1 ›amV˜m˜h¤d›F=˜/2 ˜˜,6˜3F˜1˜m=˜/2 SmartCell 6A000 User Guide Switch Administration Backing UP and Restoring Switch ConfigurationPath /backdir/config-1 ATM Routing Creating an Iisp RouteSmartCell ZX # show netprefix b2 Iisp Routing Considerations AtmAddressIisp route across Pnni domain UNI Routes 200 Route MetricsCbr 750IP Routing # show PnnimetricsZX # show route Route NETEvents and Alarms Event CategoriesViewing Events and Alarms SmartCell ZX # set eventdisplayDeleting Events and Alarms SmartCell ZX # set alarmdisplayPVC Connections SmartCell ZX # show trafficdescriptor Point-to-Point PVCsPoint-to-Multipoint PVCs 100Md1 #add trafficdescriptor Local Connecting to Local Switch Client Through a PVCNon-zero VPIs 10.1.1.0VCC Mask Index VPI Bits VPI Values VCI Bits VCI Values ZX # set vccmaskUse show portconfig to see the change to port A1 SmartCell ZX # set portconfig a1Traffic Management Traffic DescriptorsType Number Descriptor Characteristics SmartCell ZX# show trafficdescriptor5000 Call Admission Control Policy8000 ZX# add pvcUbr Min for CBR queue QoS Queue Recommended Settings SmartCell ZX # show switchtrafficcongestionEFCI, EPD, and RM Thresholds Accessing the Boot Load Prompt Upgrading and Changing SoftwareBoot Load Commands Command Action ParametersUpgrading Boot Load Software Boot PromFlash RAM =df b Upgrading Post Diagnostic Software =chpi=df p Upgrading Switch Operating Software =df sUsing the Update Firmware Command 214.95.77.240Saving Core Dumps 204.95.77.240 Tftpboot/bobr/coreSet CoreDump command BobrError IP e0103288 PFP e04be080 R0pfp e04be040 R1sp e04be0c0 Troubleshooting Troubleshooting IP Over ATMTroubleshooting LAN Emulation Troubleshooting Pnni Links Troubleshooting CongestionDiagnosing Congestion Global CongestionPort Congestion Troubleshooting Congestion Appendix a Specifications FunctionSpecification Value EjectorTable A-3 Physical Specifications Protocol Standard UNIManagement Protocol Supported MIBs RJ-45 Pin RJ-45 Color DB-9 Pin DB-9 DescriptionTechnical Specifications Appendix B Agent Support MIB, SMI, MIB Files and Internet MIB HierarchyZeitNet Cabletron Proprietary MIBs MIB, SMI, MIB Files and Internet MIB HierarchyRelation Between Object Identifier and the Represented Value Zeitnet Cabletron Proprietary MIB Groups Supported protocolsSupported SMI Formats Name Object Identifier FunctionSmartCell 6A000 MIB Support MIB Exceptions Non-ConformanceConsole Commands that Affect the Agent Update firmware Backup Restore RebootManaging the Smartcell 6A000 Managing the SmartCell 6A000 Appendix C Technical Support FAX ServiceElectronic Services Telephone AssistanceHardware Warranty Software WarrantyRepair Services Appendix D Acronyms IsdnBootp DTE FCS Ilmi LES Netbeui PDU RMA SVC VBR/RT Acronyms Appendix D-12 SmartCell 6A000 User Guide Index NumericsElan Lane Snmp Lane VPI