ENSC 427 Communication Networks

Transcription

1 1 ENSC 427 Communication Networks Final Project Demo Spring 2011 Comparison and analysis of FIFO, PQ, and WFQ Disciplines in OPNET

2 2 Introduction and Motivation Queuing methods are used to handle network resources Real-time applications such as voice and video conferencing are especially susceptible to delays and packet losses The Quality of Service (QoS) network devices must employ proper queuing methods to differentiate among arriving packets Queuing disciplines are implemented in routers We seek to provide an answer to the question: What is the best queuing discipline to use for a given application?

3 3 Focus on: Overview Comparison and analysis of queuing disciplines in OPNET FIFO First-in, First Out PQ Priority Queuing WFQ Weighted Fair Queuing Apply each queuing method towards: FTP Voice Video Conferencing

4 4 Overview Global and Object statistics collected and analyzed Statistics for Global Statistics FTP VoIP Traffic Sent Traffic Received End-to-End Delay Jitter Mean Opinion Score Packet Delay Variation Traffic Sent Traffic Received Statistics for Point-to-point Object Statistics Average Queuing Delay -> Throughput -> Utilization -> Video Conferencing End-to-End Delay Packet Delay Variation Traffic Sent Traffic Received IP Traffic Dropped

5 5 OPNET Implementation Scenarios and applications considered Scenario 1 Scenario 2 Scenario 3 Queuing discipline First-in, First-out Queuing Priority Queuing Weighted Fair Queuing Simulation Time 5 minutes 5 minutes 5 minutes Applications considered FTP VoIP Video Conferencing FTP VoIP Video Conferencing FTP VoIP Video Conferencing

6 6 OPNET Implementation Network Topology Campus network 10 x 10 km 5 workstations 2 routers 1 Ethernet server Application, Profile, and QoS Definitions

7 7 OPNET Implementation Application Attributes Application Definition Attributes Application Name FTP VoIP Video Conferencing Description High Load PCM Quality Speech Low Resolution Video Type of Service (ToS) Best Effort (0) Interactive Voice (6) Streaming Multimedia (4)

8 8 FTP Simulation Results Traffic Sent Traffic sent in bytes/s Application : FTP FIFO and WFQ show reasonable traffic sent PQ worst queuing discipline for FTP traffic with respect to traffic sent

9 9 FTP Simulation Results Traffic Received Traffic received in bytes/s Application : FTP WFQ shows more traffic received than FIFO over the long run PQ worst queuing discipline for FTP traffic, no traffic is received FTP Packets given lowest priority FTP traffic not sensitive to jitter, delay

10 10 Voice Simulation Results End-to-End Delay Time taken for packets to be transmitted from source to destination. Application : Voice ETE in voice and video should be small to provide natural conversation FIFO shows most ETE Delay (~ 2 sec) PQ and WFQ have lower ETE delay(~ sec)

11 11 Voice Simulation Results - Jitter Jitter is the variation in ETE Delay Application : Voice Jitter should be minimized especially in real time applications FIFO shows most jitter PQ and WFQ show less jitter than FIFO

12 12 Voice Simulation Results MOS Value Mean Opinion Score defines the perceived voice quality MOS scale : 1-5 1: Bad 2: Poor 3: Fair 4: Good 5: Excellent FIFO shows bad perceived audio quality PQ and WFQ in between fair and good perceived audio quality

13 13 Voice Simulation Results Packet Delay Variation PDV is a measure of the difference in ETE Ignores lost packets Application : Voice PDV should be minimized especially in real time applications FIFO shows most PDV PQ and WFQ show less PDV than FIFO

14 14 Voice Simulation Results Traffic Received Voice Traffic received in bytes/s Traffic received roughly equal initially Degree of loss increases over time FIFO queuing results in fewer bytes received PQ and WFQ result in more traffic received

15 15 Simulation Results IP Traffic Dropped IP traffic dropped packets/sec Drop in IP Traffic results due to insufficient queue space PQ and WFQ shows less drop in IP packets FIFO shows most drop Drop should be minimized, especially in real-time applications

16 16 Video Conferencing Simulation Results End-to-End Delay ETE delay (s) WFQ shows highest ETE because it transmits packets from all applications fairly FIFO shows no preference for packets sent, shows better ETE Delay than WFQ PQ shows smallest ETE, it is the best queuing choice for video conferencing with respect to ETE Delay

17 17 PQ is best choice for video with respect to PDV Video Conferencing Simulation Results Packet Delay Variation PDV is a measure of the difference in ETE, it ignores lost packets Application : Video PDV should be minimized especially in real time applications WFQ shows most PDV FIFO better choice than WFQ

18 18 Video Conferencing Simulation Results Traffic Received Video Traffic received in bytes/s PQ results show it is worst queuing technique for video with respect to traffic received FIFO better choice than PQ but has only 1 queue and no priority given to video packets WFQ chosen as best queuing discipline because it prioritizes packets

19 19 Point-to-Point: Router A -> Router B Simulation Results Average Queuing Delay Average Queuing Delay in (s) FIFO shows worst Average Queuing Delay PQ results show it is much better as compared with FIFO WFQ chosen as best queuing discipline in regard to the Average Queuing Delay

20 20 Point-to-Point: Router A -> Router B Simulation Results Throughput Throughput (packets/s) is the average number of packets received and transmitted by receiver and transmitter channels per second FIFO shows worst Throughput PQ results show it is much better as compared with FIFO WFQ chosen as best queuing discipline with regard to Throughput

21 21 Comparison of Results Obtained Ranking System Employed Ranking Equivalent System Numerical Value Good 1 Worse 2 Worst 3 Comparison of Collected Statistics, part 1 Statistics Collected Scenario 1: FIFO Scenario 2: PQ Scenario 3: WFQ Best Queuing Discipline IP Packets WFQ Dropped Average Queuing WFQ or PQ Delay Utilization FIFO, WFQ, or PQ Throughput WFQ

22 22 Comparison of Results Obtained Application FTP Comparison of Collected Statistics, part 2 Statistics Collected Scenario 1: FIFO Scenario 2: PQ Scenario 3: WFQ Best Queuing Discipline Traffic Sent WFQ Traffic Received WFQ End-to-End Delay WFQ or PQ Jitter PQ Mean Opinion Score PQ Voice Video Conferencing Packet Delay Variation WFQ or PQ Traffic Sent FIFO, WFQ, or PQ Traffic Received PQ End-to-End Delay PQ Packet Delay Variation PQ Traffic Sent FIFO, WFQ, or PQ Traffic Received WFQ

23 23 Voice Applications: Best: Priority Queues Worst: FIFO Conclusion Video Applications: Best: Weighted Fair Queues Worst: Priority Queues FTP Applications: Best: Weighted Fair Queues Worst: Priority Queues

24 24 Future Work Should study effects of other Queuing Disciplines such as DWRR, Custom Queues, SPQ, and SFQ Should study effects of Random-Early Drop (RED) and Drop-tail Policy Should consider various other applications such as online gaming. Should consider different voice and video qualities to better understand and justify best type of Queue to choose

25 25 References [1] S.P. Morgan. "Queueing Disciplines and Passive Congestion Control in Byte-Stream Networks." in INFOCOM '89 Proc. 8th Annu. Joint Conference IEEE Computer and Communications Societies, 1989, pp [2] L.G. Widjaja and I. Widjaja. Communication Networks. New York, NY: McGraw-Hill, 2004, pp [3] K. James, and R. Keith. "Scheduling and Policing Mechanisms. [Apr. 3, 2011]. [4] B. Dekeris, T. Adomkus, and A. Budnikas. "Analysis of QoS Assurance using Weighted Fair Queueing (WQF) Scheduling Discipline with Low Latency Queue (LLQ)." in 28th Int. Conf. Information Technology Interfaces, 2006, pp [5] P. Calyam et al. "Impact of Router Queuing Disciplines on Multimedia QoE in IPTV Deployments." in QoMEx 2009 Int. Workshop Quality of Multimedia Experience, 2009, pp [6] S. Minseok, C. Naehyuck, and S. Heonshik. "A New Queue Discipline for Various Delay and Jitter Requirements in Real-Time Packet- Switched Networks." in Proc. 7th Int. Conf. Real-Time Computing Systems and Applications, 2000, pp [7] Z. Ni, X. Lu, and D. Liu. "Simulation of Queuing Systems with Different Queuing Disciplines Based on Anylogic." in Int. Conf. Electronic Commerce and Business Intelligence, 2009, pp [8] T. Velmurugan, H. Chandra, and S. Balaji. "Comparison of Queuing Disciplines for Differentiated Services Using OPNET." In ARTCom 09 Int. Conf. Advances in Recent Technologies in Communication and Computing, 2009, pp