Cabletron Systems SEHI100TX manual Network Cable Lengths

Page 19

Chapter 3: Installation Requirements and Speciﬁcations

3.2NETWORK CABLE LENGTHS

This section details the maximum network cable lengths speciﬁed by the IEEE 802.3u standard for a Class I repeater. As stated previously, the physical size of the network is limited primarily by propagation delay. The round trip delay cannot exceed 512 bit times or 5.12 ∝s.

NOTE

A stack of ﬁve SEH hubs or four SEH hubs and one SEHI hub is equivalent to one repeater.

A 100BASE-T network might use all UTP links, all ﬁber links or a combination of both. Table 3-1 details the maximum link lengths for each type and combination of cable when used with a Class I repeater.

Figure 3-1 shows a simpliﬁed example of a network with one Class I repeater. Link segments A and B represent the longest links in the network. In this case, if both segment A and segment B are UTP, each segment may be up to 100 meters long for a maximum network length of 200 meters. If segment A is UTP and segment B is ﬁber, the maximum length of the network is 263 meters (with a maximum UTP segment length of 100 meters). If both segments A and B are ﬁber, the maximum length is 274 meters.

The maximum length of an individual UTP segment may be no

!more than 100 meters.

C AUT IO N

Table 3-1 Maximum Class I Network Cable Length

	Number of	UTP	UTP & Fiber	Fiber
	Repeaters	UTP	UTP & Fiber	Fiber
	Repeaters


	1	200 m	263 m	274 m

3-4	SEHI100TX User’s Guide

Image 19

Contents Intelligent Stackable HUB USER’S Guide SEHI100TX User’s Guide FCC Notice Cabletron SYSTEMS, INC. Program License Agreement United States Government Restricted Rights Contents Contents SEHI100TX User’s Guide Vii Chapter Introduction Using this ManualFollowing conventions are used throughout this document Document ConventionsRelated Manuals Getting HelpSehi Overview Chapter Sehi Features and OptionsSehi Features and Options Sehi FeaturesStackable Capabilities Remote Network Management Rack Mounting CapabilitiesOptional 100BASE-TX and 100BASE-FX EPIMs Cable Specifications Chapter Installation Requirements SpecificationsHubSTACK Interconnect Cable Requirements UTP Cable Speciﬁcations Multimode Speciﬁcations for the EPIM-100FX Network Cable Lengths COM Port Requirements Network Port SpecificationsPower Supply Requirements Operating SpecificationsEnvironmental Requirements Agency Approvals Physical SpecificationsUnpacking the Sehi Chapter InstallationNvram Switch Location PRE-INSTALLATION CheckoutSEHI100TX-22 Tabletop or Shelf InstallationScrews Strain-Relief Bracket Rackmount InstallationRackmount Installation Installing the Sehi in the Rack Powering UP and Stacking the Sehi Repeat steps 3 through 6 until all SEH hubs are connected Install an EPIM-100TX or an EPIM-100FX as follows Installing the EPIM-100TX or the EPIM-100FXConnecting the Sehi to the Network Chapter Connecting to the NetworkConnecting to Network Ports Sehi Network Ports Connecting a UTP Segment to an EPIM-100TXPosition X crossed over RX+ TX+ Position = Not crossed over EPIM-100FX Port Connecting a Fiber Segment to the EPIM-100FXTesting the Installation Installation Test Chapter TroubleshootingUsing Lanview Using Lanview Epim 1 RCV LED Using the Reset ButtonSetting the Nvram Switch Chapter Local Management Keyboard Conventions Function Local Management Keyboard ConventionsManagement Terminal Setup Console Cable Conﬁguration Management Terminal Setup Parameters Sehi Local Management Accessing Local ManagementFeature Selection Screen Feature Selection ScreenCommunity Name Table Screen Community Name Table ScreenEditing the Community Name Field Configuration Configuration ScreenDisplays the IP address of the Sehi Setting the Subnet Mask Setting the IP AddressUsing the Port Enable Override Setting the Default GatewayTrap Table Screen Exiting the Conﬁguration ScreenExiting the Trap Table Screen 1 Conﬁguring the Trap TableSnmp Tools Screen Snmp Tools ScreenLets you retrieve MIB objects using Snmp protocol Getting Individual OIDs Setting an OIDGetting the Next OID Walking Through OIDs Viewing Multiple OIDsCycling Through OIDs Stepping Through OIDsExiting the Snmp Tools Screen Device Statistics Screen Device Statistics ScreenDisplays the number of errors due to misaligned packets Module Number Sequence Selecting the Appropriate Module/PortUsing the Disable Port Command Using the Enable Port CommandExiting the Device Statistics Screen Epim Specifications Appendix a Epim SpecificationsEPIM-100TX EPIM-100FX Appendix B Image File Download Using Oids Setting UP a Unix Workstation AS a Tftp Server Standard Local Download Table B-1 OIDs and Settings Numerics IndexIndex-2 Power Supply Cord