3Com Hub 1000 SX See symmetric flow control, Detection, access method, devices. See also repeater

Page 62
bidirectional

2GLOSSARY

bidirectional

See symmetric flow control.

flow control

 

CSMA/CD

Carrier Sense Multiple Access/Collision Detection. Channel access

 

method used by Ethernet and IEEE 802.3 in which devices transmit only

 

after finding the data channel clear for some period. When two devices

 

transmit simultaneously, a collision occurs and the colliding devices

 

delay their retransmissions for a random length of time.

Ethernet

A local area network standard defining a physical medium and its

 

method of placing data, or packet signaling, on a cable. Access to the

 

cable is based on CSMA/CD (Carrier Sense Multiple Access/Collision

 

Detection).

Fast Ethernet

A 100 Mbps technology based on the Ethernet CSMA/CD network

 

access method.

fiber-optic cable

Cable consisting of a glass center, cladding, a buffer layer, strength

 

members, and a cable sheath. The glass center supports the

 

transmission of light signals.

flow control

A method for ensuring that a transmitting entity does not overwhelm a

 

receiving entity with data. See also asymmetric flow control, incoming

 

flow control, outgoing flow control, pause frame, symmetric flow

 

control.

forced link

A method by which devices link with fixed and matching signaling

 

capabilities. See also auto-negotiation.

full-duplex

The ability of a device or line to transmit data simultaneously in both

 

directions. See also half-duplex.

Gigabit Ethernet

A 1000 Mbps network technology that retains support for

 

10/100 Mbps Ethernet CSMA/CD networks.

half-duplex

Data transmission that can occur in two directions over a single line,

 

but in only one direction at a time. See also full-duplex.

hub

A device used to provide connectivity between network devices. Hubs

 

perform the basic repeater functions of restoring signal amplitude and

 

timing, detecting collisions, and broadcasting signals to network

 

devices. See also repeater.

Image 62
Contents A member of the 3Com SuperStack II System SuperStack II Hub 1000 SXUser Guide 3Com Corporation 5400 Bayfront Plaza Santa Clara, California UNITED STATES GOVERNMENT LEGENDSABOUT THIS GUIDE 1 INTRODUCTION CONTENTS2 INSTALLING THE HUB POST Messages A USING THE CONSOLE PORT3 MAKING CONNECTIONS TECHNICAL SUPPORT SPECIFICATIONSGLOSSARY INDEX 3COM CORPORATION LIMITED WARRANTY FCC CLASS A VERIFICATION STATEMENTPage FIGURES Page TABLES Port Configuration MenuPage Notice Type ABOUT THIS GUIDEIcon DescriptionMenu commands CommandsSETDEFAULT !0 -IP NETaddr = and buttonsGeneral Description INTRODUCTIONHub 1000 SX Full-Duplex Downlinksand Uplink OperationFlow Control Features and FunctionsINSTALLING THE HUB SuperStack II Hub 1000 SX User GuideHub Description The hub’s front and rear panels are shown in Figure Installing and Connecting the Hub4 Repeat steps 2 and 3 for the other side of the hub Maximum Cable ConnectorTable 2-1 Downlink Connections TypeColor Table 2-2 Hub 1000 SX IndicatorsIndicator StatusThe gigabit interface connector GBIC port on the rear panel of the Connecting aGBIC Module Using Optional Power SystemsPower Modules Cabling OptionsA hub connects to a UPS unit through the hub’s AC power cord Table 2-4 Advanced RPS Configuration OptionsYou can connect a UPS unit to an Advanced RPS unit as long as you do not exceed the maximum wattage 325 watts for the UPS unit. To verify that the UPS unit’s maximum wattage is not exceeded, calculate the total power consumption of all units connected to the Advanced RPS. If the result is less than 325 watts, your configuration is safe if the result is greater than 325 watts, then there are too many units connected to the Advanced RPS Page MAKING CONNECTIONS Table 3-1 Gigabit Ethernet Maximum Cable LengthsServers Power WorkgroupAggregating connecting to the network backbone. See FigureYou can use the Hub 1000 SX downlinks to aggregate 10/100 Mbps SwitchesThe Hub 1000 SX does not support bandwidth aggregation trunking Figure 3-3 Aggregated Switches Connection 3-4 CHAPTER 3 MAKING CONNECTIONSThe best use of the hub uplink is as a backbone connection to a 3Com ConnectingFigure 3-4 Mixed Connection Symptom Figure 3-6 Uplink Connection to a 10/100 Mbps SwitchTable 3-2 Troubleshooting Tips SolutionUSING THE CONSOLE PORT Requirements Connecting theWith Power Console PortConnecting the Console Port A-3 from powerTo connect the console port when the hub is disconnected DisconnectedAfter 4 minutes of inactivity, the CLI logs off automatically Logging Onmessage, return the hub to the supplier Changing the PasswordPort Settings ConfiguringTo display the Port Configuration menu Configuring Port Settings Table A-2 Port Configuration MenuA-8 APPENDIX A USING THE CONSOLE PORT Configuring Port Settings and be configured to receive pause frames Configuring Port Settings A-11 matrix, Y indicates yes and n indicates no. See Table A-3 DisplayingHub Status Table A-3 Hub Status InformationDisplaying Hub Status A-13 Restoring the Factory Default Settings A-14 APPENDIX A USING THE CONSOLE PORTentering option Updating theFirmware Image Checking theXmodem-CRC To transfer the firmware image file log in again. To restart the file transfer, repeat steps 6 and during a firmware update, the CLI displays the following messageLogging Off While saving port settings or Table A-4 File Transfer Error MessagesTable A-5 Fatal Error Messages Environmental Operating Ranges SPECIFICATIONSPhysical Dimensions Page TECHNICAL SUPPORT ServicesBoard Service Online Technical1 408 654 Access by Analog ModemAccess by Digital Modem C-2 APPENDIX C TECHNICAL SUPPORTLocal access numbers are available within the following countries Central European HQ Santa Clara, CaliforniaCzech Republic/Slovak 305 261 3266 Miami, FloridaTo obtain an RMA number, call or fax Page GLOSSARY access method Carrier Sense Multiple Access/Collision Detection. Channel accesscable is based on CSMA/CD Carrier Sense Multiple Access/Collision transmission of light signalsflow control IEEEincoming Mbpscontrol. See also asymmetric flow control, flow control, pause frame Numbers SymbolsINDEX Page Switch 9300 3-2, 3-3 Page HARDWARE 3Com Corporation LIMITED WARRANTYSTANDARD WARRANTY SERVICE SOFTWAREGOVERNING LAW FCC CLASS A VERIFICATION STATEMENTLIMITATION OF LIABILITY