NETGEAR FS 726, FS 750 manual Near End Cross Talk Next, Patch Cables, Conclusion

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Factors that affect the return loss are:

The number of transition points, as there is a connection via an RJ-45 to another connector, a patch panel, or device at each transition point.

Removing the jacket that surrounds the four pairs of twisted cable. It is highly recommended that, when RJ-45 connections are made, this is minimized to 1-1/4 inch (32 mm).

Untwisting any pair of the twisted-pair cabling. It is important that any untwisting be minimized to 3/8 inch (10 mm) for RJ-45 connections.

Cabling or bundling of multiple Category 5 cables. This is regulated by ANSI/EIA/TIA-568A-3. If not correctly implemented, this can adversely affect all cabling parameters.

Near End Cross Talk (NEXT)

This is a measure of the signal coupling from one wire to another, within a cable assembly, or among cables within a bundle. NEXT measures the amount of crosstalk disturbance energy that is detected at the near end of the link — the end where the transmitter is locat- ed. NEXT measures the amount of energy that is "returned" to the sender end. The factors that affect NEXT and crosstalk are exactly the same as outlined in the Return Loss sec- tion. The crosstalk performance is directly related to the quality of the cable installation.

Patch Cables

When installing your equipment, replace old patch panel cables that do not meet Category 5e specifications. As pointed out in the NEXT section, this near end piece of cable is critical for successful operation.

Conclusion

For optimum performance of your 1000BASE-T product, it is important to fully qualify your cable installation and ensure it meets or exceeds ANSI/EIA/TIA-568-A:1995 or ISO/IEC 11801:1995 Category 5 specifications. Install Category 5e cable where possible, including patch panel cables. Minimize transition points, jacket removal, and untwist lengths. Bundling of cables must be properly installed to meet the requirements in ANSI/EIA/TIA-568A-3.

cabling guidelines

C-7

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Contents Modular Fast Ethernet Switch Trademarks Statement of ConditionsCertificate of the Manufacturer/Importer Voluntary Control Council for Interference Vcci StatementEN 55024 Declaration of Conformity IiiCustomer Support Internet/World Wide WebContents Troubleshooting Information Technical SpecificationsConnector Pin Assignments Appendix C Cabling GuidelinesTables Tables Introduction DescriptionIntroduction Features Key FeaturesKey Features Additional Features Introduction Package Contents Physical Description Front and Back PanelsFront and Back Panels of the FS726 Switch Front and Back Panels of the FS750 Switch 10/100 Mbps RJ-45 PortsLED Mode Button and LED Descriptions Front Panel LEDsModule Bays Auto UplinkCreating Redundant Paths between Network Devices Example Reset Button Desktop Switching ApplicationsSegment Switching and Bridging from 10 Mbps to 100 Mbps Media Compatibility and ConversionExample of Media Compatibility and Conversion Applications Installation InstallationCharacteristics Requirements Preparing the SiteInstalling the Switch Installing the Switch on a Flat SurfaceInstalling the Switch in a Rack Connecting Devices to the Switch Connecting Devices to the Switch InstallationUsing Gigabit Ethernet Modules Checking the Installation Applying AC PowerInstallation Troubleshooting Troubleshooting ChartTroubleshooting Chart TroubleshootingTo is powered on and operating Additional Troubleshooting Suggestions ConfigurationSwitch Integrity Network Adapter CardsAppendix a Technical Specifications Network Protocol and Standards CompatibilityData Rate InterfacePerformance Specifications FS726 FS750Physical Specifications FS726 Environmental SpecificationsSafety Agency Approvals Electromagnetic EmissionsElectromagnetic Susceptibility Appendix B Connector PIN Assignments RJ-45 Plug and RJ-45 Connector100/1000 Mbps RJ-45 Plug and RJ-45 Connector Pin Assignments Duplex SC Plug and Duplex SC Connector Appendix C Cabling Guidelines Fast Ethernet Cable GuidelinesCabling guidelines Category 5 Cable Category 5 Cable Specifications Twisted Pair CablesTable C-1. Electrical Requirements of Category 5 Cable Figure C-1 illustrates straight-through twisted pair cable Patch Panels and Cables Cabling LengthReturn Loss Near End Cross Talk Next Patch CablesConclusion Fiber Cable Specifications Fiber Optic CablesGigabit Cable Guidelines Table C-2. Electrical Requirements of Fiber Optic CableIndex Index NETGEAR, Inc