D-Link DES-5016 manual System Rate Control, Advantages of Store and Forward

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Fast Ethernet Switching System User’s Guide

System Rate Control

The System Rate Control panel, displayed in Figure 26, allows you to set the packet forwarding rate on the DES-5016. There are two options: Store & Forward and Cut- Through.

Figure 26: System Rate Control

The DES-5016 can be set for Store and Forward or Cut-Through. This is a global setting that affects all the ports except the RS-232 port.

Store and Forward means that when the DES-5016 receives an incoming packet it “stores” the packet until the entire data packet has been received before it “forwards” the packet to a destination.

In Cut-Through mode the DES-5016 begins sending out the packet as soon as it receives the first 128 bytes of data. The first 128 bytes contain the destination of the packet.

Advantages of Store and Forward

Store and Forward only sends out valid data packets. Bad packets created by collisions on the network or damaged packets are filtered out.

Always use Store and Forward when some devices on the network run at 10 Mbps and others run at 100 Mbps.

Disadvantages of Store and Forward

Store and Forward requires more time because it receives the whole packet before sending it out. Every byte buffered is an additional eight microseconds of delay. For

Managing the DES-5016	46

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Contents DES-5016 Fast Ethernet Switching System User’s Guide Link Limited Warranty Hardware SoftwareLink Offices for Registration and Warranty Service North, Central, and South AmericaEurope and Israel Copyright Statement Wichtige Sicherheitshinweise Table of Contents Page Page About This Guide AudienceOrganization Features IntroductionPage Front Panel DES-5016TXDES-5016TF DES-5016TFRear Panel DES-5016 Rear PanelLocal Console Management Management MethodsUpdating Firmware Telnet ManagementInstalling the DES-5016 Unpacking the DES-5016Installation Options Desktop/ Shelf Installation Install Feet on BottomAttach Feet Rack Installation Attach Mounting BracketsInsert into Rack Installing Optional Modules Remove Blank Bracket Insert Optional Module Power On Connecting the DES-5016 to the Network Cable SpecificationsCopper Cable Cable Diagram Fiber Optic Cable Fiber Optic Ports PortsMDI-X Ports RS-232 PortConnecting the DES-5016 to other Switches and Hubs DES-5016 to DES-5016 ConnectionLEDs DES-5016TF LEDsCPU Module PowerDiagnostic StatusLED Act Port TX ModuleLink 100/10Port TX Module LEDs Port FX Module Link/ ActPort 100BASE-FX Module ColLit Dark Port 1000BASE-SX Module Gigabit Module LEDManaging the DES-5016 Local Console Management ∙ Data bits ∙ Parity None ∙ Stop bits ∙ Flow Control NoneTelnet ∙ Default User Name D-Link ∙ Default Password D-Link LogHelp Message Help MessagePanel Conventions Spacebar100BASE-FX/ 1000BASE-SX Switch Port Module System ConfigurationSwitch Port 1-8, 9-16 and Optional Module Configuration Console ProgramVlan Port Management Spanning Tree ConfigurationSnmp Management Configuration Trunking Port ManagementFactory Reset to Default Config Values System Configuration MenuSystem Reset System InformationSystem Information Menu Software UpdateBoot Prom Firmware Version Hardware RevisionSystem Description LAN Default GatewayMAC Address System NameSystem Reset System ResetFactory Reset Factory ResetFactory Reset Confirmation System Rate Control Advantages of Store and ForwardDisadvantages of Store and Forward Advantages of Cut-Through Disadvantages of Cut-ThroughSoftware Update Menu Software Update menuTransfer Firmware Xmodem User Account Management User Account Change MenuAccess Level PasswordConfirm Password Create New UserPage Delete Users StatusDelete Page Change Password Old PasswordNew Password Page Switch Port Configuration Switch Port Configuration Menu StatePhysical Port State PriorityFlow Control Spanning Tree Configuration Spanning Tree Configuration MenuSTA Operation Levels Bridge Priority Forward Delay TimeSpanning Tree Algorithm Root CostRoot Bridge Root PortSnmp Management Configuration Access Right Snmp Management Configuration MenuSnmp Manager Setting Snmp Community StringCold Start Snmp Trap Manager SettingAuthentication Failure Link Change EventPage Vlan Port Management Vlan Port Management Menu Vlan Port Management menuPort # Create New VlanNew Vlan Name TrunkGroupPage Delete Vlan Menu Vlan NameModify Vlan Menu Virtual LAN NameTrunking Port Management Menu Trunking Port Management menuCreate New Trunking Port New Trunking Group NameName Page Delete Trunking Port Trunking PortModify Trunking Port Trunking Port Name Modify Trunking PortCables TroubleshootingProblem Solution Post Errors Port StatesPage Diagnostic LED Appendix a DES-5016 Technical Specifications Switch SpecificationsPort Specifications Page Fast Ethernet Switching System User’s Guide General EMI Fast Ethernet Switching System User’s Guide Performance Index ActUser Name 52, 54