Enterasys Networks VH-8TX1UM, VH-8TX1MF manual Appendix B. Flow Control

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APPENDIX B. FLOW CONTROL

Flow control is a mechanism which allows you to protect the switch from overload conditions and to keep additional traffic off the network when excessive congestion will result. Figure B-1 illustrates flow control for both half- and full-duplex applications.

Figure B-1. Flow Control for Half- and Full-Duplex Applications

Each port of the switch has a transmit queue which buffers frames to be sent out on that port. In this example, large amounts of data are being sent from Workstation A (connected to port X) and other ports on the switch to Workstation B (connected to port Y).The queue on port Y starts filling up with data until it reaches a determined threshold. The packet which causes the threshold to be exceeded triggers the flow-control function on the port from which the packet entered the switch, in this case port X.

Since port X is configured with flow control set to Enabled, the switch responds by initiating a pause frame (full-duplex applications) or back- pressure mechanism (half-duplex applications). The pause frame causes Workstation A to stop sending packets. After a certain amount of time has elapsed, determined by a value in the pause frame, Workstation A will resume sending data. Similarly, the back-pressure mechanism forces Workstation A to stop sending packets by inducing collisions on port X.

The pause-frame flow-control mechanism supported by the VH-8TX1UM/VH-8TX1MF switch conforms with the IEEE 802.3x specification for full-duplex flow control.

For the full-duplex pause-frame mechanism to work, the device connected to the switch port must also support IEEE 802.3x flow control. Flow control is configurable per port in the Port Configuration Menu of the console menus, using the on-board Web agent, or via SNMP.

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Contents User Guide Vertical Horizon VH-8TX1UM/VH-8TX1MF Fast Ethernet SwitchPage 9033718-01 FCC Notice Warnhinweis Faseroptikanschlüsse Optische Sicherheit Safety Information Wichtige Sicherheitshinweise Germany Enterasys NETWORKS, INC Program License Agreement Viii Declaration of Conformity 9033718-01 Table of Contents Index Purpose PrefaceAudience ConventionsOther Conventions OrganizationDescription Product OverviewTftp FeaturesFront Panel Components Front PanelRear Panel Feature SummariesIeee 802.1D Bridge Spanning Tree ProtocolFrame Buffering and Frame Latency Configuration and Management InterfacesSoftware Download Non-Volatile Parameter StorageRmon Auto-negotiation Port MirroringMulticast Filtering Port SecurityBootP Configuration Upload/DownloadFull-Duplex Mode Broadcast SuppressionClass of Service Virtual LANs VLANsPort Trunking Factory Default Settings Factory DefaultsApplication Examples Client/Server Network Application Client/Server Network ApplicationLocal Backbone Application Local Backbone ApplicationVH-8TX1UM/VH-8TX1MF Installation Inspecting Your ShipmentSite Requirements Mounting the Switch on a Table or Shelf Mounting the Switch in a Rack Mounting the Switch in a RackConsole Port Out-of-Band Connections Connecting a Terminal to the Console PortIn-Band Connections Remote Management via the Console PortConnecting the Power Cord Powering the SwitchNetwork Cable Requirements CopperFiber 10Base-T/100Base-TX Ports Inserting an RJ-45 Connector into a Port100Base-FX Fiber Port Inserting an SC Fiber Connector into the Fiber PortVH-8TX1UM/VH-8TX1MF General Appendix A. Technical SpecificationsPhysical Specifications Electrical SpecificationsPort Specifications Console Port10Base-T and 100Base-TX Ports Power Cord Set Requirements MDI/MDI-X Crossover Cable WiringGeneral Requirements Country-Specific Requirements Table A-3. Power Cord Set Requirements by CountryVH-8TX1UM/VH-8TX1MF Appendix B. Flow Control VH-8TX1MF Term Definition Appendix C. Acronyms & AbbreviationsUTP Index Index Web-based network manager Xmodem download, 5 VH-8TX1MF Page 150728-102 R02

VH-8TX1MF, VH-8TX1UM specifications

Enterasys Networks, a well-respected name in the field of networking technology, has introduced the VH-8TX1UM and VH-8TX1MF models, which cater to the ever-evolving needs of modern enterprises. These devices are designed to enhance connectivity, improve network performance, and provide enhanced security for users across various environments.

The VH-8TX1UM model is a versatile Layer 2/3 managed switch that features eight 10/100/1000BASE-T Ethernet ports. This configuration allows for seamless connectivity with existing network infrastructure while providing the necessary throughput for bandwidth-hungry applications. It supports a range of features including VLAN tagging, port mirroring, and link aggregation, making it ideal for both small and medium-sized businesses looking to scale their networks without significant hardware investments.

Meanwhile, the VH-8TX1MF model is designed with a focus on modularity. It not only features eight Ethernet ports but also includes slots for additional modules, allowing organizations to customize their network setup based on specific requirements. The modular design ensures flexibility, enabling future upgrades without the need for complete hardware replacements. This characteristic is particularly beneficial for companies that anticipate growth or changes in their network architecture.

Both models boast advanced technologies such as Quality of Service (QoS) and Power over Ethernet (PoE). QoS prioritizes critical network traffic, ensuring that voice and video applications receive the bandwidth they need for optimal performance. PoE allows for the powering of devices like IP cameras, phones, and wireless access points directly through the Ethernet cables, simplifying installations and reducing the need for additional power sources.

In terms of security, Enterasys equips the VH-8TX1UM and VH-8TX1MF with robust features to safeguard sensitive data. These include access control lists and port security settings, which protect against unauthorized access and mitigate potential threats. Additionally, the switches support network management protocols such as Simple Network Management Protocol (SNMP), enabling efficient monitoring and management of network performance.

Overall, the Enterasys VH-8TX1UM and VH-8TX1MF models stand out with their combination of performance, flexibility, and security. They present a compelling option for enterprises aiming to enhance their networking capabilities while ensuring that they are well-equipped to handle future technological advancements. Businesses investing in these switches are sure to benefit from a solid foundation that can evolve with their operational needs.
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