六龙回日Quality of Service (QoS)
Test Plan
Contents
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QoS Overview and Deploymentt (3)
1. Layer -3 Stateless QoS Functional Test (4)
. Layer 4-7 Stateful QoS Functional Test (8)
3. Triple Play QoS Functional Test (11)
4.Conclusion (14)
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Quality of Service (QoS) Test Plan
数码经络按摩仪QoS Overview and
Deploymentt The implementation of Quality of Service mechanisms is a critical element to solving th
e problems of handling the increasing volume and disparate types of traffic en on today’s public and private networks. Whenever a mission critical application – whether voice, video, or data – is being delivered over a network, Quality of Service traffic shaping and policing can assist network managers in maintaining the best network performance and good-put for applications during periods of network congestion.
QoS offers the following core principles:
Classification and Marking
Policing
Queuing and Dropping
Both Class of Service (CoS) and ToS IP Precedence (or DSCP) are Quality of Service methods ud to manage the network during congestion.
Class of Service allows the network administrator to identify the order of priority that the incoming traffic be procesd for transmission when the switch or network is congested. As an example, a weighted round robin (WRR) method prevents head-of-line blocking. Network administrator can tu
p the queues to match various business requirements and priority levels. The IEEE 802.1p standard recommends the Class of Service traffic categories described in Table 1.
Priority Type of Traffic Equivalent Application Traffic
红丹参0 (lowest)Best effort Ordinary LAN priority traffic
1Background File transfers, games, AIM
(spare)Not ud
3Excellent effort For critical urs applications
4Controlled load For important applications
5Video, < 100ms latency and jitter Video application or mix with Voice
6Voice, < 10ms latency and jitter Voice application
7 (highest)Network control Critical traffic to maintain network
Table 1. Class of Service traffic parameters
布洛芬功效
IP Precedence allows the network administrator to prioritize IP traffic. Using the ToS IP Precedence or DSCP fields, the network administrator can design the edge switch or router to effectively classify, mark, and process packets according to the application requirements. Most critical application traffic takes precedence over any routine traffic processing. The IP Precedence consists of 3 bits, while the DSCP consists of 6 bits (64 possible values). Ixia’s IP testing solutions can help meet the challenging requirements for QoS testing and assist in the benchmarking and pre-deployment analysis of network devices and systems. Solutions are provided with Ixia’s Layer 2/3 IxScriptMate and IxExplorer applications, as well as the Layer 4 bad IxChariot stateful network traffic emulation tool. Examples of the usage of the applications to execute QoS test cas are described in this document.
This test plan provides a framework and structure for custom test plan development to meet individual test requirements.
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Objectives Measure the baline performance of the DUT with and without QoS when stateless traffic is injected into the network. Stateless traffic is Layer 2 -3 data and does not emulate true ur application traffic. This test verifies that the latency and the packets loss on the egress traffic change to much lower values when QoS is enabled on the receiving DUT. Without enabling QoS both the latency and packets loss are much higher. The 1st step is to take measurements and collect statistics when QoS is disabled on the DUT. The 2nd step is to take measurement and collect statistics when QoS with IP Precedence classifying and marking is enabled on the DUT. Setup The baline tup for this test requires four test ports. Three ports are ud to generate Layer 3 traffic connected to three DUT ports. The connections are considered the ingress ports to the DUT or the network. Each port carries a parate stream with a specific IP Precedence marked value. The fourth test port is connected to a fourth DUT port to evaluate the outgoing network traffic (egress) bad on the QoS rvice characteristics and ttings. See Figure 1.
Ixia’s IxScriptMate Many-to-One test can help tup and execute this test ca.Figure 1. Many-to-O
护肤品代购ne QoS test tup Input Parameters Two ts of parameters are required prior to running the Layer 2/3 QoS functional test. One t of parameters are for the test tool and the other for the DUT. Table 2 lists the test parameters.1. Layer 2-3 Stateless QoS Functional Test
Parameters Description Frame size Packet frame size can bet t for fixed or random Duration Test Duration to run ranges from hours down to conds.Traffic Rate Traffic rate per priority level DUT- QoS Administrative DUT QoS tting (enabled or disabled)DUT-Line speed The link / interface speeds of the DUT ports DUT-QoS type DUT QoS type ttings: COS, ToS IP Precedence, or DSCP DUT-QoS Policies DUT QoS Policies applied to the ingress traffic DUT-Queue type Queuing mechanism such as Weighted Random Early Detection (WRED) and Weighted Round Robin (WRR) Queuing Table 2. QoS Input Parameters Table Methodology TEST 1- QoS is disabled on the DUT With QoS is disabled on the DUT, configure the network according to Figure 1.Setup the simulated traffic rate per type. Refer to Figure 2. Refer to Table 2 for input parameters required to t up the traffic and the test.Start the traffic and run for the test duration.The traffic is received by the DUT and is not prioritized or classified. See Figure 3. Note the latency measurements and values and the packet loss percentage in Figure 4 and 5.TEST 2- QoS is enabled on the DUT Enable QoS on the DUT and rerun the same test.The traffic that is received (ingress) by the DUT is classified, prioritized
and procesd accordingly. The resultant traffic (egress port) is measured for Packet Loss, and Latency.
Obrve the new latency measurements and the packet loss (refer to Figures 6, 7 and 8)Figure 2. Test Setup 1. .3.4.1. .3.
