Cabletron Systems STHI General Networking Considerations, Maximum Number of Stations on a Ring

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CHAPTER 2

Requirements & Speciﬁcations

This chapter describes network guidelines, power requirements, and operating specifications for the STHI. Before performing the installation, read this chapter and confirm that the network meets the requirements and conditions specified herein. Failure to follow these guidelines may result in poor network performance.

Refer to Appendix A, TPIM Specifications, for TPIM specifications.

Refer to Appendix B, Media Specifications, for cable specifications.

2.1 General Networking Considerations

Take care in planning and preparing the cabling and connections for the network. The susceptibility of the LAN’s cables to crosstalk and noise determines the network’s error rate, and thus, the efficiency of data propagation on the network. The quality of the connections, the length of cables and other conditions of the installation are critical factors in determining the quality of the network.

All devices connected to the STHI must meet IEEE 802.5 Token Ring specifications.

Maximum Number of Stations on a Ring

1

The maximum stack composed of four 24-port STH hubs and one 24-port STHI offers a total of 120 TCU ports, but the number of ports available on the LAN may be increased by the use of passive Multi-Station Access Units (see to Section 1.2.6, Support for Passive MAU Workgroups) and TPIM Ring In / Ring Out connections to other devices (see Section 1.2.3, RI & RO Ports).

While there is no recommended limit to the number of TCU ports to be made available in a stack, the recommended maximum number of stations to be inserted simultaneously into a single ring is 255 when using STP lobe cabling and 150 when using UTP cabling anywhere on the ring. If the ring has been extended through RI/RO connections, consider the number of ports on ring extensions as well as those in the stack itself.

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Contents Sthi Intelligent Token Ring Stackable HUB USER’S Guide Page FCC Notice Cabletron Software Program License United States Government Restricted Rights Installation Requirements & SpecificationsIntroduction Local Management TroubleshootingAppendix a Tpim Specifications Appendix B Media Specifications Sthi Overview Contents of This ManualLanview LEDs Sthi OverviewRing Speed Fault Protection Lobe Port and Multiple Ring Out Port ConfigurationsTCU Ports 3 RI & RO Ports Daughter Board Upgrade KitMedia Type Connector Active CircuitryHub-By-Hub Bypass Control Automatic Beacon Recovery ProcessSupport for Passive MAU Workgroups Flash Downloads Improved Protection from BeaconingIP Address Discovery DAISY-CHAIN MAU Configuration Local Management Related ManualsGetting Help Related ManualsGetting Help Maximum Number of Stations on a Ring General Networking ConsiderationsCrosstalk TemperatureInstallation Recommendations General Networking ConsiderationsTCU and COM Ports Operating SpecificationsOperating Specifications Hubstack Interconnect CablesRJ45 to DB25 Connector Pinout Ring Speed Supported MIB GroupsStandard MIBs Cabletron Enterprise MIBsRing Sequence SafetyComputing Hardware Physical SpecificationsEnvironmental Requirements Unpacking the Sthi Installing the SthiRack-Mounting the Sthi Installing the SthiStacking the Sthi Attaching the Strain Relief BracketRack Mounting Brackets Wall-Mounting the SthiInstalling the Sthi Wall-mounting the Sthi Free-Standing InstallationsConnecting the Sthi to the Power Source Tpim InstallationFinishing the Installation Tpim InstallationColor Condition Lanview LED SignalsFailure to Link on Enabled Port Trouble ResolutionTrouble Resolution Loss Of PowerManagement Failure Reset ButtonReset Button Reset ButtonNvram Reset Switch Nvram Reset SwitchLocal Management Accessing LMDumb Terminal Configuration Accessing LMMenu Parameter Setting Entering LM Console Cable ConfigurationWorking with LM Screens Using LM ScreensUsing LM Screens Invoking Menu Options or Screen CommandsExiting the Local Management Interface Session Setting or Modifying FieldsSystem Level Password Screen Main Menu Device Setup StatusScreen Hierarchy Screen IntroductionsDevice Statistics Snmp TrapsChassis Status View Component StatusIP Address System Level ScreenSystem Level Screen System Date and System TimeSubnet Mask Enable IP Address DiscoveryRetry Interval Number of Retries Enable Beacon RecoveryMAC Address Locally Administered AddressSnmp Community Names Screen Snmp Community Names ScreenRead-write Access PolicyCommunity Name Read-onlyTrap Destination Enable TrapsSnmp Traps Screen Snmp Traps ScreenFunctions of the Chassis Status View Screen Screen Mode Screen CommandChassis Status View Screen Chassis Status View ScreenMultiplexer Configuration Fields Administrative Mode Port Configuration FieldsEach port field whether Tpim or TCU may be set as follows Ring OUT Enable Mode Each Ring port Tpim port or Ring Out TCU may be listed as Operational ModeComponent Status Screen Component Status ScreenNext and Previous Device Statistics Screen Device Statistics ScreenAccumulate Screen ModeBeacon States Errors ReceivedFrames Received KBytes ReceivedStations on a Ring Ports EnabledRing Status Ring NumberAC Errors Isolating Errors Fields GroupLine Errors Burst ErrorsFrame Copied Errors Internal ErrorsNon-Isolating Errors Group Lost Frame ErrorsSnmp Tool Screen Token ErrorsFrequency Errors Snmp Tool Screen3 GET OID PrependStep GetnextCycles Walk9 SET Firmware Image Downloads RepeatCtDLCommitRAMtoFlash Twisted Pair Tpim Pinouts OverviewFiber Optic Tpim Specifications Fiber Optic Tpim SpecificationsParameter Typical Worst Case TPIM-F2 for Multimode FiberBudget Parameter Typical Minimum Maximum TPIM-F3 for Single Mode FiberA-5 UTP Cable Categories Unshielded Twisted Pair UTPPer 100m @ ≥100m Operating Electrical SignalUnshielded Twisted Pair UTP Attenuation Loss Cat FrequencyCategory Shielded Twisted Pair STPShielded Twisted Pair STP @ 4 Mbps @ 16 MbpsMixed STP Cable Types Operational Attenuation perType Frequency 1000 m 1000 ft STP Lobe LengthsTotal Maximum Single Mode and Multimode Fiber Optic CablingSingle Mode and Multimode Fiber Optic Cabling Max. Lobe Length Max. Drive Distance Type Mbps