Cabletron Systems SmartCell 6A000 manual EFCI, EPD, and RM Thresholds

Page 57

Switch Administration

Traffic Management

Class of Service Queue Allocation Guidelines

The following are recommended settings for the Min and Max thresholds for the class of service queues under specific sustained traffic conditions. Use these settings as guidelines for threshold settings:

•CBR — fewer than 100 connections on a port: Min = 50, Max = 1000

•CBR — more than 100 connections on a port: Min = 100, Max = 1000

•rt-VBR — bandwidth utilization less than 20%: Min = 10, Max = 1000*

•rt-VBR — bandwidth utilization more than 20 %: Min = 100, Max = 4000*

•Nrt-VBR — for port B4 (CPU): Min = 100, Max = 4000

•Nrt-VBR — for all other ports: Min = 10, Max = 1000

•UBR — Min = 32, Max = 16,000

* Use the show cacstats command to view bandwidth utilization.

4.6.4EFCI, EPD, and RM Thresholds

To control switch congestion, the SmartCell 6A000 implements standard resource management cell (RM-cell) marking, explicit forward congestion indicator cell marking (with backward RM cell marking), and early packet discard (EPD). These congestion control schemes are triggered when the number of cells within shared memory reaches user definable thresholds. Use the switchtrafficcongestion command to view and set these thresholds.

For example, enter the show switchtrafficcongestion command.

SmartCell ZX # show switchtrafficcongestion

Switch Traffic Congestion Parameters

============================================================================

Queue 1

EFCI

Threshold

: 4096 cells

Queue 2

EFCI

Threshold

: 4096 cells

Queue 3

EFCI

Threshold

: 4096 cells

Queue 4

EFCI

Threshold

: 4096 cells

Low EPD

Threshold

: 10922 cells

High EPD Threshold

: 21845 cells

Switch Discard Threshold

: 30508 cells

RM Cell

Marking Enable

: ON

EFCI Cell Marking Enable

: ON

SmartCell ZX

#

 

EFCI thresholds are set on a per class of service queue basis, while EPD thresholds are set with respect to the total amount of shared buffer space being used by all classes of service.

For most types of traffic, EPD triggering is tied to the low EPD threshold. Signaling traffic, however, is tied to the high EPD threshold to assure that signaling packets are discarded only when congestion is most severe.

Use the set switchtrafficcongestion command to change thresholds for EFCI and EPD and to enable or disable RM and EFCI cell marking.

Along with EFCI and backward RM cell marking, the SmartCell 6A000 uses standard RM cell marking. The switch discard threshold (show switchtrafficcongestion) corresponds to total shared buffer utilization and represents the point at which the switch considers itself congested and starts marking RM cells.

The switch discard threshold is not user configurable and is shown only for information.

For information on troubleshooting congestion problems, see Chapter 5, "Troubleshooting."

SmartCell 6A000 User Guide 4-23

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Contents Order number Part number 04-0045-01 Rev. a SmartCell 6A000 User GuideIi 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 Troubleshooting Acronyms Index Table of Contents 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 Unpacking the Switch Switch Installation and SetupInspecting the Switch Check Accessory Carton Contents6A000-04 and 6A000-02 front panels Mbps STS-3c/STM-1 UTP5, 4 Ports Installing the SwitchInstalling the Switch Installing the SmartCell 6A000 Adapters provided for connecting to the switch Configuring the Switch6A000 console and network connections Console Commands Using the ConsoleAdding and Modifying ClientEnter Console Help ServerAddress 390000000000000000001441800020d414418001UNIATMAddress 390000000000000000001441800020d414418000 Creating AN IP Over ATM Vlan IP Over ATM and LaneIpatmarp ATM Addressing for IP over ATMSmartCell ZX # add wellknownaddress Creating AN Emulated LANELANType802.3 The default Ethernet is used ATM Addressing for LAN Emulation ELANs Across Multiple Switches Switch ClientsElan1 Switch Administration Backing UP and Restoring Switch ConfigurationPath /backdir/config-1 Path server.ima Upgrading Operating SoftwareSetting UP Routes Unsuccessful UpdateUsing the df Command to Recover Creating Iisp Routes Iisp RoutingSmartCell ZX # show netprefix a4 ATMAdress 39000000000000000000144780 SW2s netprefixIisp Routes Among Multiple Switches ATMAdress 39000000000000000000141500 SW3s netprefixATMAdress 39000000000000000000144180 SW1s netprefix Iisp routes between multiple switches Default Iisp RoutesIisp Routes and Network Topology For example, create a default Iisp route from port B1Routing Loops 112255 112244UNI Routes SigConfig and PortAutoDetect with Iisp RoutingIisp Metrics and Load Sharing UNIATMAddress 440000000000000000001441800030E514418000IP Routing To see the route, enter the show route command on SW2 Logs and AlarmsHow Log Messages and Alarm Messages Differ Log Message SystemViewing and Filtering Messages Console Setting UP PVC ConnectionsPoint-to-Point PVCs Connecting to Local Client Through Point-to-Point PVC100 10.1.1.0Point-to-Multipoint PVCs Show vccmask Non-zero VPIsSmartCell ZX # show portconfig a1 SmartCell ZX # set portconfig a1Traffic Descriptors Traffic Management5000 8000Call Admission Control Policy # set cacparams Class of Service QueuesPortNumberALL Port ID Queue Class of Service Queue Allocation Guidelines SmartCell ZX # show switchtrafficcongestionEFCI, EPD, and RM Thresholds Traffic Management Troubleshooting Troubleshooting IP Over ATMLogprint off command Troubleshooting LAN Emulation Troubleshooting Congestion Diagnosing CongestionGlobal Congestion Port Congestion Troubleshooting TroubleshootingCongestion Troubleshooting Congestion Appendix a Features and Specifications Hardware ComponentsFront Panel Figure A-1 Front panel CPU ModuleInput/Output Port Modules Switch Modules MSM and ESMModule TypeCharacteristics Figure A-3 Group and port identifiers Port NumberingSwitch Module FeaturesSignaling and Routing 3 I/O ModulesLAN Servers and Clients Connection ManagementManagement ATM Forum LAN Emulation LaneSpecifications Technical SpecificationsPhysical Specifications Standards Specifications ATM Port SpecificationsRJ-45 DB-25 Pin Color Description CPU Serial Port Pin-Out DescriptionsTable A-11 RJ-45 to DB-25 Adapter Modem Adapter Appendix A-12 SmartCell 6A000 User Guide Internet MIB Hierarchy Appendix B Smartcell 6A000 and SnmpFigure B-1 Internet MIB Hierarchy Zeitnet Proprietary MIBFigure B-2 ZeitNet Private MIBs Interpreting the Object IdentifierProprietary MIB Functions Client for Snmp Management Console Commands That Affect the AgentMIB Exceptions Non-ConformanceNot Supported SmartCell 6A000 User Guide Appendix B-7 Page Electronic Services FAX ServiceAppendix C Technical Support Telephone AssistanceHardware Warranty Software WarrantyRepair Services Appendix D Acronyms Can CACCBR CcittDTE DCCDVT NETFifo FCSFTP IeeeIP/ATM IOMIPX ITU-TSSLeselan LESLIS LLCNFS NetbeuiNIC NLSPMD PDUPMP PPDSAR SaalSAR-PDU SBETCP TaxiTDM TftpVCI VCCVCL VlanAcronyms Appendix D-12 SmartCell 6A000 User Guide Index Add wellknownaddress command 3-6 AddressSetting up routes Vlan Index SmartCell 6A000 User Guide
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