Role and Mechanism of Queue Internet Engineering.

Slides:

Advertisements

Similar presentations

ECE358: Computer Networks Fall 2014

Advertisements

Ns-2 Tutorial Exercise (1) Multimedia Networking Group, The Department of Computer Science, UVA Jianping Wang Adopted from Nicolas’s slides Jianping Wang,

Computer Networks Performance Metrics Computer Networks Term B10.

1 CNPA B Nasser S. Abouzakhar Queuing Disciplines Week 8 – Lecture 2 16 th November, 2009.

1 CONGESTION CONTROL. 2 Congestion Control When one part of the subnet (e.g. one or more routers in an area) becomes overloaded, congestion results. Because.

Fundamentals of Computer Networks ECE 478/578

1.  Congestion Control Congestion Control  Factors that Cause Congestion Factors that Cause Congestion  Congestion Control vs Flow Control Congestion.

TCP and FTP Internet Engineering. 1 Protocol of transport layer Reliability （ guarantee packet arrives to destination ） –Retransmission control Use for.

CS 268: Lecture 8 Router Support for Congestion Control Ion Stoica Computer Science Division Department of Electrical Engineering and Computer Sciences.

CS 408 Computer Networks Congestion Control (from Chapter 05)

1 ELEN 602 Lecture 18 Packet switches Traffic Management.

NETWORK LAYER. CONGESTION CONTROL In congestion control we try to avoid traffic congestion. Traffic Descriptor Traffic descriptors are qualitative values.

1 Core-Stateless Fair Queueing: A Scalable Architecture to Approximate Fair Bandwidth Allocations in High Speed Networks Core-Stateless Fair Queueing:

Computer Networks Computer Networks Term B10 Network Delay Network Delay Performance Problems.

CS 381 Introduction to computer networks Chapter 1 - Lecture 3 2/5/2015.

Texas A & M University1 Impact of bandwidth-delay product and non-responsive flows on the performance of queue management schemes Zhili.

Buffer Sizing for Congested Internet Links Chi Yin Cheung Cs 395 Advanced Networking.

Lecture 2 Introduction 1-1 Chapter 1: roadmap 1.1 What is the Internet? 1.2 Network edge  end systems, access networks, links 1.3 Network core  circuit.

EECS122 – Lecture 5 Department of Electrical Engineering and Computer Sciences University of California Berkeley.

Katz, Stoica F04 EECS 122: Introduction to Computer Networks Performance Modeling Computer Science Division Department of Electrical Engineering and Computer.

CS 268: Lecture 8 (Router Support for Congestion Control) Ion Stoica February 19, 2002.

1 Emulating AQM from End Hosts Presenters: Syed Zaidi Ivor Rodrigues.

Data Communication and Networks

Lecture Internet Overview: roadmap 1.1 What is the Internet? 1.2 Network edge  end systems, access networks, links 1.3 Network core  circuit switching,

1 Comnet 2006 Communication Networks Recitation 10 QoS.

Lecture Internet Overview: roadmap 1.1 What is the Internet? 1.2 Network edge  end systems, access networks, links 1.3 Network core  circuit switching,

Lecture 2 Performance Metrics. Bandwidth Delay Bandwidth-delay product Latency Throughput.

1 Kommunikatsiooniteenuste arendus IRT0080 Loeng 7 Avo Ots telekommunikatsiooni õppetool, TTÜ raadio- ja sidetehnika inst.

Computer Networks Performance Metrics. Performance Metrics Outline Generic Performance Metrics Network performance Measures Components of Hop and End-to-End.

1 Lecture 14 High-speed TCP connections Wraparound Keeping the pipeline full Estimating RTT Fairness of TCP congestion control Internet resource allocation.

UDP and CBR Internet Engineering. 1 Contents Delivery Encode –Music or movie is converted to data (compress) CBR (Constant Bit Rate) –Constant bit assignment.

Computer Networks Performance Metrics

Network Simulator-2 Sandeep singla 1998A2A7540. NS-2 A discrete event simulator Focused on modeling network protocols –Wired, wireless –TCP,UDP,unicast,multicast.

TNK092: Network Simulation - Nätverkssimulering Lecture 3: TCP Vangelis Angelakis.

ICOM 6115©Manuel Rodriguez-Martinez ICOM 6115 – Computer Networks and the WWW Manuel Rodriguez-Martinez, Ph.D. Lecture 7.

CSC 581 Communication Networks II Chapter 7c: Congestion Control Dr. Cheer-Sun Yang.

ECE466 - Tutorial Simple Delay and Throughput Analysis.

IT 210: Web-based IT Winter 2012 Measuring Speed on the Internet and WWW.

STORE AND FORWARD & CUT THROUGH FORWARD Switches can use different forwarding techniques— two of these are store-and-forward switching and cut-through.

Deadline-based Resource Management for Information- Centric Networks Somaya Arianfar, Pasi Sarolahti, Jörg Ott Aalto University, Department of Communications.

What is the Speed of the Internet? Internet Computing KUT Youn-Hee Han.

T. S. Eugene Ngeugeneng at cs.rice.edu Rice University1 COMP/ELEC 429 Introduction to Computer Networks Lecture 18: Quality of Service Slides used with.

We used ns-2 network simulator [5] to evaluate RED-DT and compare its performance to RED [1], FRED [2], LQD [3], and CHOKe [4]. All simulation scenarios.

1 Core-Stateless Fair Queueing: A Scalable Architecture to Approximate Fair Bandwidth Allocations in High Speed Networks Core-Stateless Fair Queueing:

Queuing Delay 1. Access Delay Some protocols require a sender to “gain access” to the channel –The channel is shared and some time is used trying to determine.

CSE 413: Computer Network Circuit Switching and Packet Switching Networks Md. Kamrul Hasan

Delay in packet switched network. Circuit switching In Circuit switched networks the resources needed along a path (buffers and link transmission rate)

Spring Computer Networks1 Congestion Control Sections 6.1 – 6.4 Outline Preliminaries Queuing Discipline Reacting to Congestion Avoiding Congestion.

Network Topology. Network Topology Cont. Sender = 0 and Receiver = 5 Sender = 0 and Receiver = 5 Sender transmits ftp traffic over TCP/IP to receiver.

Univ. of TehranIntroduction to Computer Network1 An Introduction Computer Networks An Introduction to Computer Networks University of Tehran Dept. of EE.

1 Lecture 15 Internet resource allocation and QoS Resource Reservation Protocol Integrated Services Differentiated Services.

Chapter 10 Congestion Control in Data Networks and Internets 1 Chapter 10 Congestion Control in Data Networks and Internets.

Doc.: IEEE /577r0 Submission July 2003 Qiang NI, Pierre Ansel, Thierry Turletti, INRIASlide 1 A Fair Scheduling Scheme for HCF Qiang Ni, Pierre.

Empirically Characterizing the Buffer Behaviour of Real Devices

Introduction to ns-2: “The” Network Simulator

Chapter 6 Queuing Disciplines

Queue Dynamics with Window Flow Control

CONGESTION CONTROL.

EE 122: Router Support for Congestion Control: RED and Fair Queueing

William Stallings Data and Computer Communications

Congestion Control (from Chapter 05)

Congestion Control (from Chapter 05)

Network Simulation NET441

COMP/ELEC 429 Introduction to Computer Networks

Congestion Control (from Chapter 05)

Congestion Control (from Chapter 05)

Congestion Control (from Chapter 05)

Congestion Control (from Chapter 05)

Congestion Control (from Chapter 05)

Congestion Control (from Chapter 05)

Presentation transcript:

Role and Mechanism of Queue Internet Engineering

1 What is Queue （ buffer ） Packet exchange ＝ Store – and – forward –Router temporary stores packet in buffer Packet is queued and then stored （ In Drop Tail ） earlier income packet will transmit soon, what comes in first is handled –If the queue overflows, packets will be dropped Router Queue （ buffer ）

Internet Engineering 2 Relationship between Node, Queue, Link Packet Queue (Buffer) LinkNode Node 0 Node 2Node 3Node 4 In NS2, each link has a queue Packets go through queue before sent out to the link If input rate is larger than output rate, overflow packets will be accumulated in queue –It can response to temporary traffic increase –Packet are dropped if queue length exceeds its capacity Bandwidth

Internet Engineering 3 Packet flow Observe the packet （ ID=62 ）（ % awk ‘$12==62’ out.tr ） ※ experiment １ - １ -(b): bandwidth 4Mbps Node 0Node 2Node 3Node cbr cbr r cbr cbr cbr r cbr cbr cbr r cbr Mbps 6ms 40Mbps 6ms 4Mbps 20ms 84ms 62ms 22ms Why?

Internet Engineering 4 Time for forwarding packet Node 0Node 2Node 3Node 4 40Mbps 6ms 40Mbps 6ms 4Mbps 20ms Queuing time in queue ＋ Forwarding time ＋ Time for transmission between links → (Queue length)×(Time for sending packet out) ※ Queue length ： the number of packet kept in queue, 31 in this ex → (Packet size [bytes])÷(Bandwidth of Link [Mbps]) 1000[bytes] 4[Mbps] → （ Link delay ） Time for sending packet from node 2 to node 3 62ms 2ms 20ms Total 84ms

Internet Engineering 5 Packet flow （ Dropped packet ） Observe packet （ ID=63 ） by （ % awk ‘$12==63’ out.tr ） ※ In experiment １ - １ -(b), bandwidth is 4Mbps Node 0Node 2Node 3Node cbr cbr r cbr cbr d cbr Mbps 6ms 40Mbps 6ms 4Mbps 20ms Drop Dropped after join a queue

Internet Engineering 6 Experiment 2 Consider following relationship –Sending traffic rate –Bandwidth of bottleneck link –Queue length –Number of bytes discarded from queue CBR/UDP Bandwidth: Bw (Bottleneck link) 40Mbps Queue Size: B

Internet Engineering 7 【 Supplement 】 Execution of Experiment 2 % ns problem2.tcl 1.0Mb 32 –out.tr out.nam out.queue out.udp are created % gnuplot gnuplot> l “problem2.gp” gnuplot> … gnuplot> set term post color gnuplot> set output “graph.ps” gnuplot> rep gnuplot> q If you don’t like the format, you can modify kadai1-2.gp (Bw)(B)(B)

Internet Engineering 8 【 Supplement 】 out.queue content out.queue (Trace file of queue) –$1 : time –$2, $3 : position of queue （ link ） –$4 : accumulated data in queue (queue length) [bytes] –$5 : accumulated packet number in queue [packets] –$6 : number of packets arrived to queue [packets] –$7 : number of packets sent out from queue [packets] –$8 : number of packets dropped by queue [packets] –$9 : amount of data arrived to queue [bytes] –$10 : amount of data send out from queue [bytes] –$11 : amount of data dropped by queue [bytes] ※ $5 ～ $11 is cumulative value from start of simulation

Internet Engineering 9 【 Supplement 】 out.udp content out.udp (Trace file of UDP) –$1 : time –$2 : send traffic rate [Mbps] –$3 : bandwidth of bottleneck link [Mbps]

Internet Engineering 10 Example of graph （ attention point ） ※ In experiment 2 when Bw is 1.0Mbps and B is 32kbytes 31