Traffic Prioritization, Your Switch | 3Com 3 manual

50CHAPTER 6: USING TRAFFIC PRIORITIZATION

Figure 12 DSCP Service Level Mapping

Ingress Port

Classification

DSCP

DSCP

Service levels

Service Level 2

Best Effort

Service Level 3 Business Critical

Service Level 4

Video Applications

Service Level 5

Voice Applications

Service Level 6

Internetwork Control

Service Level 7

Network Control

Strict Priority

Queue Scheduling

Low Priority Queue

High Priority Queue

All

Egress Ports

	Figure 12 illustrates how DiffServ code point (DSCP) service levels are
	mapped to the two Traffic Queues.
	The DSCP service level of the packet is not altered by the Switch 4200.

Traffic Prioritization	The traffic should be marked as it enters the network; the marking can be
and your Switch	achieved in two ways:
	■ The original device can apply the DSCP or 802.1p markings to the
	packet before transmission.
	■ The edge port on the Switch connecting the originating device can
	classify and mark or re-mark the packets before sending them to the
	network. This is not done by the Switch 4200, an intermediate device
	in the network is required to do this.
	Received packets in the Switch 4200 are checked for DSCP classification
	and IEEE 802.1D priority. The Switch 4200 does not set or modify priority
	levels within the packet.
	The transmitting endstation sets the priority of each packet. When the
	packet is received, the Switch places the packet into the appropriate
	queue, depending on its priority level, for onward transmission across the
	network. The Switch determines which queue to service next through its
	Strict Priority queuing mechanism. This method services both traffic
	queues, giving priority to the high priority queue.

Image 50

3Com 3 manual Traffic Prioritization, Your Switch

Contents

SuperStack 3Com Corporation 5400 Bayfront Plaza Santa Clara, California Contents Using Multicast Filtering Status Monitoring and Statistics IP Addressing About this Guide Conventions List conventions that are used throughout this guide Comments RelatedDocumentation Pddtechpubscomments@3com.com Product Registration Switch Features Page Management What isSwitch Features Software? Switch Features Overview Duplex Ports operating at 1000 Mbps only support full duplex modeFor more information about multicast filtering, see Using Flow Control For more information about STP and RSTP, see Using Resilience Features Event Notification Quality of ServiceFor more information about Quality of Service, see Using For more information about VLANs, see Setting Up Virtual Port Features Ports operating at 1000 Mbps support full duplex mode only Port Features Switch units connected using an aggregated link Aggregated Links Traffic Distribution and Link Failure on Aggregated Links 2 Gbps aggregated link between two Switch units Optimizing Bandwidth Using Multicast Filtering Relevant multicast group Using Multicast Filtering Query Mode Query modeSnooping Mode Igmp multicast filtering works as follows Igmp v2 protocolThat support IP Enabling Igmp Multicast Learning Igmp Multicast Filtering Using Multicast Filtering Network Spanning TreeProtocol STP Ieee 802.1w standard What is STP? Traffic flowing through Bridge B Port Speed Link Type Path Cost 802.1D-1998 802.1w Using Resilience Features Port costs in a network Configuration 3 Redundancy for Cabling Error Configuration 1 Redundancy for Backbone LinkConfiguration 2 Redundancy through Meshed Backbone STP configurations Network with Default BehaviorUsing STP on a Multiple VLANs Configuration that separates VLANs Using Resilience Features Database? What is the SwitchHow Switch Database Entries Switch Database Entry States Databases entries can have three states Available What is TrafficPrioritization? Converged network applications Used by organizations with a 802.1D Priority Levels How Traffic Prioritization Works Your Switch Traffic Prioritization How traffic is processed to provide Quality of Service Configuring traffic prioritization for QoS on a Switch Using Traffic Prioritization That allows you to monitor the traffic of LANs or VLANs What is RMON?Network efficiency and reduce the load on your network It improves your efficiency AlarmsEvents Switch Rmon Low Threshold Statistic High Threshold Recovery Period Low Threshold Statistic High Threshold Recovery Status Monitoring and Statistics Hardware Status Monitoring Example device summary web Setting UP Virtual Lans VLANs ease the movement of devices on networks VLANs provide extra security VLANs help to control traffic Membership Creating an Ieee 802.1Q Tagged Link Two Vlans connected via a router Configure the VLANs ConfigurationUsing Untagged Examples Add ports to the VLANs Configure the VLANs on SwitchAdd endstation ports on Switch 1 to the VLANs Add port 11 on Switch 2 to the VLANs Add port 12 on Switch 1 to the VLANsAdd endstation ports on Switch 2 to the VLANs Check the Vlan membership for both switches Configuration Information How Your SwitchObtains IP How Automatic IP How Automatic IP Configuration Works Considerations Automatic IP configuration featureThat a Switch may change its IP address whilst in use Glossary Configuration RulesIP Addressing IndexPage Configuration Rules Configuration Rules for Gigabit Ethernet Fast Ethernet configuration rules Configuration Rules for Fast Ethernet Appendix a Configuration Rules Network This chapter contains the following sections Family and 4900 family can be used in your network Segments are connected to the Switch which is positionedSimple Network Example Dual Speed Hub Switch Resilience of Your Advanced NetworkImproving Network Therefore the overall network performance EnhancingPerformance IP Addresses Simple Overview Obtaining a Registered IP Address IP Address Network Portion Dotted Decimal NotationDecimal value of an octet whose bits are all 1s is Subnet mask Subnet Mask Numbering Extending the Network Prefix Or leave the field blank Glossary Glossary Ethernet address EndstationEthernet Fast Ethernet Hub GatewayHalf duplex Ieee 802.1D Line speed See baud Glossary Rstp See Rapid Spanning Tree Protocol STP See Spanning Tree Protocol STP Page Glossary Index Numbers Igmp multicast filtering 30 Internet Addresses 85 InterNIC Sub-networks. See subnets Switch Database