3Com 510M-FBP, 5102M-FBP, 5104M-FB1 Sample Configuration Distance Calculation

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Figure 2-8. Sample Configuration Distance Calculation

To determine if your network configuration is legal:

1.Use 4200 m as the maximum network diameter for a pure fiber network as defined by the 802.3 specification.

2.Calculate the equivalent distances for each concentrator, and subtract the total from 4200 (see figures for details).

3.Subtract all cable lengths between the two transceivers and if the result is greater than zero, the configuration is within legal Ethernet limits (Rule 5).

For the configuration shown in Figure 2-8 to work, ensure the fiber equivalent distance between Transceiver A and Transceiver B is less than 4200 meters. As shown in the calculation, there are still 1510 meters left for expansion in this configuration. Therefore, this configuration is legal.

Designing and Expanding the Network 2 - 23

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Contents Page VDE Class B Compliance Restricted Rights Page Contents Installing and Operating the Module Appendix a Specifications Page Figures Page Tables Page Audience How to Use This GuideStructure of This Guide Usr/snm/agents Document ConventionsConvention Indicates Example 3Com Documents Related DocumentsReference Documents Slot ONline System Concentrator Installation and OperationPage Introduction 10BASE-FB Module Descriptions Introduction 1 Theory of Operation 10BASE-FB ComplianceBASE-FB Module Connections 3Com Product Part Number Compatibility With Other Ethernet Fiber ProductsBASE-FB Module Compatibility Designing and Expanding the Network Rule Definition Recommendations/Notes Rules for Configuring a NetworkUnderstanding the General Rules Basic Network RulesDefinition Recommendations/Notes Is actually equal to 1.1 meters LAN Product Equivalent Fiber Equivalent Fiber DistancesEquivalent Fiber Distances of LAN Products Determining Maximum Fiber Link Distances Determining Link Budget Calculating Maximum Link DistanceDBm ONline 10BASE-FB Module Optical Power Budget Normal PowerPower Link Link LossONline to ONline 10BASE-FB Module Optical Power Budget High PowerBASE-FB Optical Power Budget Cable Size Used Transmit Receive Optical Power MicronAttenuation Typical Fiber Loss Characteristics Connector and Splice Insertion LossMeter Fiber Link With Mechanical Splice Example 1700 Meter Fiber Link With Mechanical SpliceMeter Fiber Link Through Two Patch Panels Example 2000 Meter Fiber Link Through Two Patch PanelsChoosing a Network Backbone Cabling Structure Star-Wiring Configuration Star ConfigurationSerial Configuration Using 10BASE-FB Modules Serial ConfigurationFiber Backbone, Fiber-to-the-Desk 10BASE-FB Module ConfigurationsAll-Fiber Network Network With 3 Concentrators Example Network With 3 ConcentratorsExample Network with 8 Concentrators Network Configured With 8 ConcentratorsFiber Equivalent Distances Between Transceivers Fiber Backbone, Unshielded Twisted Pair to-the-Desk Example Sample Configuration Distance CalculationSample Configuration Distance Calculation Fiber Backbone, Coaxial Connection Example Connecting a Thin Ethernet 10BASE2 SegmentDesigning and Expanding the Network 2 Standard Redundant Configuration In this configuration Fault-Tolerant ConfigurationsConfiguring Ports for Fault Tolerance Setting Redundancy 10. Redundant Fiber Backbone Configuration Implementing Total Backbone Fault Tolerance 11. Total Backbone Fault-Tolerant Configuration 12. Fiber Network With 3 Concentrators Page Installing and Operating the Module Precautionary Procedures Unpacking Procedures Step Procedure Section Title Quick InstallationQuick Installation Procedures Setting the Dip Switches BASE-FB Module Dip Switch Locations Switch Label Function Factory Switch Setting Default Off Setting Dip Switch S1Dip Switch S1 Settings for Switches 1 Channel Selection Dip Switch S1 Settings for Switches 3 toPort-Switching Module Port Module-Switching ModuleSwitch Label Function Factory Switch Setting Default Setting Dip Switch S2Dip Switch S2 Settings Enable/disable Disable Module Low Light Detection Not Used Installing the ModuleInstalling the 10BASE-FB Module BASE-FB Module Connection Configuring the Module Enabling Ports Selecting a Network Enabling Port Redundancy You can enable port redundancy in one of the following waysEnabling Low Light Warning Enabling Optical PowerSaving Module Configuration Showing Module ConfigurationMonitoring the Front Panel Page LED Name Color State Indicates Interpreting the 10BASE-FB Module LEDsNetwork Check Codes LED State Network ConfigurationVerifying LED and Network Assignments Troubleshooting Possible Cause Corrective Action Troubleshooting Using the Port Activity LEDsTroubleshooting Using the Port Activity LEDs LED State Indication Possible Cause Corrective Action Troubleshooting Using the Port Status LEDsTroubleshooting Using the Port Status LEDs Troubleshooting Using the Port Status LEDs Troubleshooting Using the Port Status LEDs 10BASE-FL Technical Assistance Page Specifications Table A-1. General Specifications General SpecificationsCable Type Normal Power High Power Optical SpecificationsTransmitter Specifications Table A-2. Transmit PowerSupported Fiber Optic Cables Receiver SpecificationsTable A-3. Receiver Specifications Fiber Optic Interface Power RequirementsTable A-4. Fiber Optic Interface Specifications Table A-5. Power RequirementsTable A-7. Mechanical Specifications Environmental SpecificationsMechanical Specifications Table A-6. Electrical Specifications10BASE-FB Cables 10BASE-FB Cable and Connector SpecificationsTable A-8 BASE-FB Module Part Numbers 10BASE-FB ConnectorsPort-Switching Connector Type On-line Technical Support Technical SupportWorld Wide Web Site Support from Your Network SupplierEmail Technical Support Support from 3Com Returning Products for Repair Accessing the 3Com MIB3Com Technical Publications Page Index Installing Link Budget Redundant Link, 3-16Redundancy LED Unpacking Procedures, 3-3Unshielded Twisted Pair Cable