Congestion Control. Srinidhi Varadarajan
|
|
- William Bennett
- 7 years ago
- Views:
Transcription
1 Congestion Control Srinidhi Varadarajan
2 Principles of Congestion Control Congestion: informally: too many sources sending too much data too fast for network to handle different from flow control! manifestations: lost packets (buffer overflow at routers) long delays (queuing in router buffers) a top-10 problem!
3 Causes/costs of congestion: scenario 1 two senders, two receivers one router, infinite buffers no retransmission large delays when congested maximum achievable throughput
4 Causes/costs of congestion: scenario 2 one router, finite buffers sender retransmission of lost packet
5 Causes/costs of congestion: scenario 2 always: λ = λ (goodput) in out perfect retransmission only when loss: λ > λ in out retransmission of delayed (not lost) packet makes λ larger in (than perfect case) for same λ out costs of congestion: more work (retrans) for given goodput unneeded retransmissions: link carries multiple copies of pkt
6 Causes/costs of congestion: scenario 3 four senders multihop paths timeout/retransmit Q: what happens as and increase? λ in λ in
7 Causes/costs of congestion: scenario 3 Another cost of congestion: when packet dropped, any upstream transmission capacity used for that packet was wasted!
8 Approaches towards congestion control Two broad approaches towards congestion control: End-end congestion control: no explicit feedback from network congestion inferred from end-system observed loss, delay approach taken by TCP Network-assisted congestion control: routers provide feedback to end systems single bit indicating congestion (SNA, DECbit, TCP/IP ECN, ATM) explicit rate sender should send at
9 Case study: ATM AB congestion control AB: available bit rate: elastic service if sender s path underloaded : sender should use available bandwidth if sender s path congested: sender throttled to minimum guaranteed rate M (resource management) cells: sent by sender, interspersed with data cells bits in M cell set by switches ( network-assisted ) NI bit: no increase in rate (mild congestion) CI bit: congestion indication M cells returned to sender by receiver, with bits intact
10 Case study: ATM AB congestion control two-byte E (explicit rate) field in M cell congested switch may lower E value in cell sender send rate thus minimum supportable rate on path EFCI bit in data cells: set to 1 in congested switch if data cell preceding M cell has EFCI set, receiver sets CI bit in returned M cell
11 TCP Congestion Control end-end control (no network assistance) transmission rate limited by congestion window size, Congwin, over segments: Congwin w segments, each with MSS bytes sent in one TT: throughput = w * MSS TT Bytes/sec
12 TCP congestion control: probing for usable bandwidth: ideally: transmit as fast as possible (Congwin as large as possible) without loss increase Congwin until loss (congestion) loss: decrease Congwin, then begin probing (increasing) again two phases slow start congestion avoidance important variables: Congwin threshold: defines threshold between two slow start phase, congestion control phase
13 TCP Slowstart Slowstart algorithm initialize: Congwin = 1 for (each segment ACKed) Congwin++ until (loss event O CongWin > threshold) TT Host A Host B one segment two segments four segments exponential increase (per TT) in window size (not so slow!) loss event: timeout (Tahoe TCP) and/or or three duplicate ACKs (eno TCP) time
14 TCP Congestion Avoidance Congestion avoidance /* slowstart is over */ /* Congwin > threshold */ Until (loss event) { every w segments ACKed: Congwin++ } threshold = Congwin/2 Congwin = 1 1 perform slowstart 1: TCP eno skips slowstart (fast recovery) after three duplicate ACKs
15 AIMD TCP congestion avoidance: AIMD: additive increase, multiplicative decrease increase window by 1 per TT decrease window by factor of 2 on loss event TCP Fairness Fairness goal: if N TCP sessions share same bottleneck link, each should get 1/N of link capacity TCP connection 1 TCP connection 2 bottleneck router capacity
16 Why is TCP fair? Two competing sessions: Additive increase gives slope of 1, as throughout increases multiplicative decrease decreases throughput proportionally equal bandwidth share Connection 2 throughput Connection 1 throughput loss: decrease window by factor of 2 congestion avoidance: additive increase loss: decrease window by factor of 2 congestion avoidance: additive increase
17 TCP latency modeling Q: How long does it take to receive an object from a Web server after sending a request? TCP connection establishment data transfer delay Two cases to consider: Notation, assumptions: Assume one link between client and server of rate Assume: fixed congestion window, W segments S: MSS (bits) O: object size (bits) no retransmissions (no loss, no corruption) WS/ > TT + S/: ACK for first segment in window returns before window s worth of data sent WS/ < TT + S/: wait for ACK after sending window s worth of data sent
18 TCP latency Modeling K:= O/WS Case 1: latency = 2TT + O/ Case 2: latency = 2TT + O/ + (K-1)[S/ + TT - WS/]
19 TCP Latency Modeling: Slow Start Now suppose window grows according to slow start. Will show that the latency of one object of size O is: Latency = O S P 2TT + + P TT (2 1) + S where P is the number of times TCP stalls at server: P = min{ Q, K 1} - where Q is the number of times the server would stall if the object were of infinite size. - and K is the number of windows that cover the object.
20 TCP Latency Modeling: Slow Start (cont.) Example: O/S = 15 segments K = 4 windows Q = 2 P = min{k-1,q} = 2 initiate TCP connection request object TT first window = S/ second window = 2S/ third window = 4S/ Server stalls P=2 times. fourth window = 8S/ object delivered time at client time at server complete transmission
21 TCP Latency Modeling: Slow Start (cont.) S + TT = time from when server starts to send segment until server receives acknowledgement k S 2 1 = time to transmit the kth window initiate TCP connection request object first window = S/ S + TT + k S 2 1 = stall time after the kth window TT second window = 2S/ third window = 4S/ latency = O + 2TT + P p= 1 stalltime p fourth window = 8S/ = = O O + 2TT + 2TT + P k= 1 [ S + P[ TT + + TT S 2 ] (2 k 1 P S ] 1) S object delivered time at client time at server complete transmission
Outline. TCP connection setup/data transfer. 15-441 Computer Networking. TCP Reliability. Congestion sources and collapse. Congestion control basics
Outline 15-441 Computer Networking Lecture 8 TCP & Congestion Control TCP connection setup/data transfer TCP Reliability Congestion sources and collapse Congestion control basics Lecture 8: 09-23-2002
More informationLecture 15: Congestion Control. CSE 123: Computer Networks Stefan Savage
Lecture 15: Congestion Control CSE 123: Computer Networks Stefan Savage Overview Yesterday: TCP & UDP overview Connection setup Flow control: resource exhaustion at end node Today: Congestion control Resource
More informationData Networks Summer 2007 Homework #3
Data Networks Summer Homework # Assigned June 8, Due June in class Name: Email: Student ID: Problem Total Points Problem ( points) Host A is transferring a file of size L to host B using a TCP connection.
More informationTCP in Wireless Mobile Networks
TCP in Wireless Mobile Networks 1 Outline Introduction to transport layer Introduction to TCP (Internet) congestion control Congestion control in wireless networks 2 Transport Layer v.s. Network Layer
More informationFirst Midterm for ECE374 03/09/12 Solution!!
1 First Midterm for ECE374 03/09/12 Solution!! Instructions: Put your name and student number on each sheet of paper! The exam is closed book. You have 90 minutes to complete the exam. Be a smart exam
More informationRouter-assisted congestion control. Lecture 8 CS 653, Fall 2010
Router-assisted congestion control Lecture 8 CS 653, Fall 2010 TCP congestion control performs poorly as bandwidth or delay increases Shown analytically in [Low01] and via simulations Avg. TCP Utilization
More informationTCP over Multi-hop Wireless Networks * Overview of Transmission Control Protocol / Internet Protocol (TCP/IP) Internet Protocol (IP)
TCP over Multi-hop Wireless Networks * Overview of Transmission Control Protocol / Internet Protocol (TCP/IP) *Slides adapted from a talk given by Nitin Vaidya. Wireless Computing and Network Systems Page
More informationChapter 6 Congestion Control and Resource Allocation
Chapter 6 Congestion Control and Resource Allocation 6.3 TCP Congestion Control Additive Increase/Multiplicative Decrease (AIMD) o Basic idea: repeatedly increase transmission rate until congestion occurs;
More informationTransport Layer Protocols
Transport Layer Protocols Version. Transport layer performs two main tasks for the application layer by using the network layer. It provides end to end communication between two applications, and implements
More informationTCP over Wireless Networks
TCP over Wireless Networks Raj Jain Professor of Computer Science and Engineering Washington University in Saint Louis Saint Louis, MO 63130 Audio/Video recordings of this lecture are available at: http://www.cse.wustl.edu/~jain/cse574-10/
More informationFirst Midterm for ECE374 03/24/11 Solution!!
1 First Midterm for ECE374 03/24/11 Solution!! Note: In all written assignments, please show as much of your work as you can. Even if you get a wrong answer, you can get partial credit if you show your
More informationTransport layer issues in ad hoc wireless networks Dmitrij Lagutin, dlagutin@cc.hut.fi
Transport layer issues in ad hoc wireless networks Dmitrij Lagutin, dlagutin@cc.hut.fi 1. Introduction Ad hoc wireless networks pose a big challenge for transport layer protocol and transport layer protocols
More informationA Survey on Congestion Control Mechanisms for Performance Improvement of TCP
A Survey on Congestion Control Mechanisms for Performance Improvement of TCP Shital N. Karande Department of Computer Science Engineering, VIT, Pune, Maharashtra, India Sanjesh S. Pawale Department of
More informationImproving the Performance of TCP Using Window Adjustment Procedure and Bandwidth Estimation
Improving the Performance of TCP Using Window Adjustment Procedure and Bandwidth Estimation R.Navaneethakrishnan Assistant Professor (SG) Bharathiyar College of Engineering and Technology, Karaikal, India.
More informationCS268 Exam Solutions. 1) End-to-End (20 pts)
CS268 Exam Solutions General comments: ) If you would like a re-grade, submit in email a complete explanation of why your solution should be re-graded. Quote parts of your solution if necessary. In person
More informationQuestion: 3 When using Application Intelligence, Server Time may be defined as.
1 Network General - 1T6-521 Application Performance Analysis and Troubleshooting Question: 1 One component in an application turn is. A. Server response time B. Network process time C. Application response
More informationTCP for Wireless Networks
TCP for Wireless Networks Outline Motivation TCP mechanisms Indirect TCP Snooping TCP Mobile TCP Fast retransmit/recovery Transmission freezing Selective retransmission Transaction oriented TCP Adapted
More informationTCP Westwood for Wireless
TCP Westwood for Wireless מבוא רקע טכני בקרת עומס ב- TCP TCP על קשר אלחוטי שיפור תפוקה עם פרוטוקול TCP Westwood סיכום.1.2.3.4.5 Seminar in Computer Networks and Distributed Systems Hadassah College Spring
More informationFinal for ECE374 05/06/13 Solution!!
1 Final for ECE374 05/06/13 Solution!! Instructions: Put your name and student number on each sheet of paper! The exam is closed book. You have 90 minutes to complete the exam. Be a smart exam taker -
More informationTCP Flow Control. TCP Receiver Window. Sliding Window. Computer Networks. Lecture 30: Flow Control, Reliable Delivery
TCP Flow Control Computer Networks The receiver side of a TCP connection maintains a receiver buffer: Lecture : Flow Control, eliable elivery application process may be slow at reading from the buffer
More informationSimulation-Based Comparisons of Solutions for TCP Packet Reordering in Wireless Network
Simulation-Based Comparisons of Solutions for TCP Packet Reordering in Wireless Network 作 者 :Daiqin Yang, Ka-Cheong Leung, and Victor O. K. Li 出 處 :Wireless Communications and Networking Conference, 2007.WCNC
More informationTCP, Active Queue Management and QoS
TCP, Active Queue Management and QoS Don Towsley UMass Amherst towsley@cs.umass.edu Collaborators: W. Gong, C. Hollot, V. Misra Outline motivation TCP friendliness/fairness bottleneck invariant principle
More informationComputer Networks - CS132/EECS148 - Spring 2013 ------------------------------------------------------------------------------
Computer Networks - CS132/EECS148 - Spring 2013 Instructor: Karim El Defrawy Assignment 3 - Solutions Deadline : May 9 th 9:30pm (hard and soft copies required) ------------------------------------------------------------------------------
More informationTCP and Wireless Networks Classical Approaches Optimizations TCP for 2.5G/3G Systems. Lehrstuhl für Informatik 4 Kommunikation und verteilte Systeme
Chapter 2 Technical Basics: Layer 1 Methods for Medium Access: Layer 2 Chapter 3 Wireless Networks: Bluetooth, WLAN, WirelessMAN, WirelessWAN Mobile Networks: GSM, GPRS, UMTS Chapter 4 Mobility on the
More informationTCP/IP Over Lossy Links - TCP SACK without Congestion Control
Wireless Random Packet Networking, Part II: TCP/IP Over Lossy Links - TCP SACK without Congestion Control Roland Kempter The University of Alberta, June 17 th, 2004 Department of Electrical And Computer
More information1. The subnet must prevent additional packets from entering the congested region until those already present can be processed.
Congestion Control When one part of the subnet (e.g. one or more routers in an area) becomes overloaded, congestion results. Because routers are receiving packets faster than they can forward them, one
More informationCongestions and Control Mechanisms n Wired and Wireless Networks
International OPEN ACCESS Journal ISSN: 2249-6645 Of Modern Engineering Research (IJMER) Congestions and Control Mechanisms n Wired and Wireless Networks MD Gulzar 1, B Mahender 2, Mr.B.Buchibabu 3 1 (Asst
More information2 TCP-like Design. Answer
Homework 3 1 DNS Suppose you have a Host C, a local name server L, and authoritative name servers A root, A com, and A google.com, where the naming convention A x means that the name server knows about
More information15-441: Computer Networks Homework 2 Solution
5-44: omputer Networks Homework 2 Solution Assigned: September 25, 2002. Due: October 7, 2002 in class. In this homework you will test your understanding of the TP concepts taught in class including flow
More informationMobile Communications Chapter 9: Mobile Transport Layer
Mobile Communications Chapter 9: Mobile Transport Layer Motivation TCP-mechanisms Classical approaches Indirect TCP Snooping TCP Mobile TCP PEPs in general Additional optimizations Fast retransmit/recovery
More informationApplication Level Congestion Control Enhancements in High BDP Networks. Anupama Sundaresan
Application Level Congestion Control Enhancements in High BDP Networks Anupama Sundaresan Organization Introduction Motivation Implementation Experiments and Results Conclusions 2 Developing a Grid service
More informationAn enhanced TCP mechanism Fast-TCP in IP networks with wireless links
Wireless Networks 6 (2000) 375 379 375 An enhanced TCP mechanism Fast-TCP in IP networks with wireless links Jian Ma a, Jussi Ruutu b and Jing Wu c a Nokia China R&D Center, No. 10, He Ping Li Dong Jie,
More informationLow-rate TCP-targeted Denial of Service Attack Defense
Low-rate TCP-targeted Denial of Service Attack Defense Johnny Tsao Petros Efstathopoulos University of California, Los Angeles, Computer Science Department Los Angeles, CA E-mail: {johnny5t, pefstath}@cs.ucla.edu
More informationEINDHOVEN UNIVERSITY OF TECHNOLOGY Department of Mathematics and Computer Science
EINDHOVEN UNIVERSITY OF TECHNOLOGY Department of Mathematics and Computer Science Examination Computer Networks (2IC15) on Monday, June 22 nd 2009, 9.00h-12.00h. First read the entire examination. There
More informationVisualizations and Correlations in Troubleshooting
Visualizations and Correlations in Troubleshooting Kevin Burns Comcast kevin_burns@cable.comcast.com 1 Comcast Technology Groups Cable CMTS, Modem, Edge Services Backbone Transport, Routing Converged Regional
More informationA Qos SCHEME TO ADDRESS COMMUNICATION LATENCY ISSUES FOR CRITICAL NETWORK FLOWS IN BEST-EFFORT NETWORKS USING MOBILE AGENTS
A Qos SCHEME TO ADDRESS COMMUNICATION LATENCY ISSUES FOR CRITICAL NETWORK FLOWS IN BEST-EFFORT NETWORKS USING MOBILE AGENTS Visvasuresh Victor * Gergely Zaruba G. Balasekaran Govindaswamy University of
More informationPrefix AggregaNon. Company X and Company Y connect to the same ISP, and they are assigned the prefixes:
Data Transfer Consider transferring an enormous file of L bytes from Host A to B using a MSS of 1460 bytes and a 66 byte header. What is the maximum value of L such that TCP sequence numbers are not exhausted?
More informationProtagonist International Journal of Management And Technology (PIJMT) Online ISSN- 2394-3742. Vol 2 No 3 (May-2015) Active Queue Management
Protagonist International Journal of Management And Technology (PIJMT) Online ISSN- 2394-3742 Vol 2 No 3 (May-2015) Active Queue Management For Transmission Congestion control Manu Yadav M.Tech Student
More informationCongestion Control Review. 15-441 Computer Networking. Resource Management Approaches. Traffic and Resource Management. What is congestion control?
Congestion Control Review What is congestion control? 15-441 Computer Networking What is the principle of TCP? Lecture 22 Queue Management and QoS 2 Traffic and Resource Management Resource Management
More informationChaoyang University of Technology, Taiwan, ROC. {changb,s9227623}@mail.cyut.edu.tw 2 Department of Computer Science and Information Engineering
TCP-Taichung: A RTT-based Predictive Bandwidth Based with Optimal Shrink Factor for TCP Congestion Control in Heterogeneous Wired and Wireless Networks Ben-Jye Chang 1, Shu-Yu Lin 1, and Ying-Hsin Liang
More information17: Queue Management. Queuing. Mark Handley
17: Queue Management Mark Handley Queuing The primary purpose of a queue in an IP router is to smooth out bursty arrivals, so that the network utilization can be high. But queues add delay and cause jitter.
More informationAnalytic Models for the Latency and Steady-State Throughput of TCP Tahoe, Reno and SACK
REVISION 1 1 Analytic Models for the Latency and Steady-State Throughput of TCP Tahoe, Reno and SACK B. Sikdar, S. Kalyanaraman and K. S. Vastola Dept. of ECSE, Rensselaer Polytechnic Institute Troy, NY
More informationPer-Flow Queuing Allot's Approach to Bandwidth Management
White Paper Per-Flow Queuing Allot's Approach to Bandwidth Management Allot Communications, July 2006. All Rights Reserved. Table of Contents Executive Overview... 3 Understanding TCP/IP... 4 What is Bandwidth
More informationLecture Objectives. Lecture 07 Mobile Networks: TCP in Wireless Networks. Agenda. TCP Flow Control. Flow Control Can Limit Throughput (1)
Lecture Objectives Wireless and Mobile Systems Design Lecture 07 Mobile Networks: TCP in Wireless Networks Describe TCP s flow control mechanism Describe operation of TCP Reno and TCP Vegas, including
More informationAn Improved TCP Congestion Control Algorithm for Wireless Networks
An Improved TCP Congestion Control Algorithm for Wireless Networks Ahmed Khurshid Department of Computer Science University of Illinois at Urbana-Champaign Illinois, USA khurshi1@illinois.edu Md. Humayun
More informationUsing Fuzzy Logic Control to Provide Intelligent Traffic Management Service for High-Speed Networks ABSTRACT:
Using Fuzzy Logic Control to Provide Intelligent Traffic Management Service for High-Speed Networks ABSTRACT: In view of the fast-growing Internet traffic, this paper propose a distributed traffic management
More informationTCP Adaptation for MPI on Long-and-Fat Networks
TCP Adaptation for MPI on Long-and-Fat Networks Motohiko Matsuda, Tomohiro Kudoh Yuetsu Kodama, Ryousei Takano Grid Technology Research Center Yutaka Ishikawa The University of Tokyo Outline Background
More informationAN IMPROVED SNOOP FOR TCP RENO AND TCP SACK IN WIRED-CUM- WIRELESS NETWORKS
AN IMPROVED SNOOP FOR TCP RENO AND TCP SACK IN WIRED-CUM- WIRELESS NETWORKS Srikanth Tiyyagura Department of Computer Science and Engineering JNTUA College of Engg., pulivendula, Andhra Pradesh, India.
More informationSample Network Analysis Report
Sample Network Analysis Report Report Information Report created on 1/9/2014 9:35:19 PM. Analyst Information Name Sample Analysis Report E-mail Address info@chappellu.com Phone Number 408-378-7841 Client
More informationThe Problem with TCP. Overcoming TCP s Drawbacks
White Paper on managed file transfers How to Optimize File Transfers Increase file transfer speeds in poor performing networks FileCatalyst Page 1 of 6 Introduction With the proliferation of the Internet,
More informationICTCP: Incast Congestion Control for TCP in Data Center Networks
ICTCP: Incast Congestion Control for TCP in Data Center Networks Haitao Wu, Zhenqian Feng, Chuanxiong Guo, Yongguang Zhang {hwu, v-zhfe, chguo, ygz}@microsoft.com, Microsoft Research Asia, China School
More informationTCP over High Speed Variable Capacity Links: A Simulation Study for Bandwidth Allocation
TCP over High Speed Variable Capacity Links: A Simulation Study for Bandwidth Allocation Henrik Abrahamsson, Olof Hagsand and Ian Marsh SICS AB, Kista S- 9, Sweden {henrik, ianm}@sics.se Dynarc AB, Kista
More informationMultipath TCP in Practice (Work in Progress) Mark Handley Damon Wischik Costin Raiciu Alan Ford
Multipath TCP in Practice (Work in Progress) Mark Handley Damon Wischik Costin Raiciu Alan Ford The difference between theory and practice is in theory somewhat smaller than in practice. In theory, this
More informationTransport layer protocols for ad hoc networks
Transport layer protocols for ad hoc networks Lecturer: Dmitri A. Moltchanov E-mail: moltchan@cs.tut.fi http://www.cs.tut.fi/kurssit/tlt-2616/ Which transport layer protocol? Classification of transport
More informationMidterm Exam CMPSCI 453: Computer Networks Fall 2011 Prof. Jim Kurose
Midterm Exam CMPSCI 453: Computer Networks Fall 2011 Prof. Jim Kurose Instructions: There are 4 questions on this exam. Please use two exam blue books answer questions 1, 2 in one book, and the remaining
More informationSCTP over Satellite Networks
1 SCTP over Satellite Networks Shaojian Fu Mohammed Atiquzzaman School of Computer Science University of Oklahoma, Norman, OK 73019-6151. William Ivancic Satellite Networks & Architectures Branch NASA
More informationInternational Journal of Scientific & Engineering Research, Volume 6, Issue 7, July-2015 1169 ISSN 2229-5518
International Journal of Scientific & Engineering Research, Volume 6, Issue 7, July-2015 1169 Comparison of TCP I-Vegas with TCP Vegas in Wired-cum-Wireless Network Nitin Jain & Dr. Neelam Srivastava Abstract
More informationTCP/IP In Cellular Networks
TCP/IP In Cellular Networks Two Techniques To Improve TCP Performance In Cellular Networks UNC Wireless Networks 790-088 November, 29 2010 John DeArmon M-TCP: TCP for Cellular Networks Improving TCP Performance
More information[Prof. Rupesh G Vaishnav] Page 1
Basics The function of transport layer is to provide a reliable end-to-end communications service. It also provides data transfer service for the user layers above and shield the upper layers from the
More informationApplications. Network Application Performance Analysis. Laboratory. Objective. Overview
Laboratory 12 Applications Network Application Performance Analysis Objective The objective of this lab is to analyze the performance of an Internet application protocol and its relation to the underlying
More informationCSE 473 Introduction to Computer Networks. Exam 2 Solutions. Your name: 10/31/2013
CSE 473 Introduction to Computer Networks Jon Turner Exam Solutions Your name: 0/3/03. (0 points). Consider a circular DHT with 7 nodes numbered 0,,...,6, where the nodes cache key-values pairs for 60
More informationActive Queue Management (AQM) based Internet Congestion Control
Active Queue Management (AQM) based Internet Congestion Control October 1 2002 Seungwan Ryu (sryu@eng.buffalo.edu) PhD Student of IE Department University at Buffalo Contents Internet Congestion Control
More informationPART III. OPS-based wide area networks
PART III OPS-based wide area networks Chapter 7 Introduction to the OPS-based wide area network 7.1 State-of-the-art In this thesis, we consider the general switch architecture with full connectivity
More informationTCP in Wireless Networks
Outline Lecture 10 TCP Performance and QoS in Wireless s TCP Performance in wireless networks TCP performance in asymmetric networks WAP Kurose-Ross: Chapter 3, 6.8 On-line: TCP over Wireless Systems Problems
More informationA packet-reordering solution to wireless losses in transmission control protocol
Wireless Netw () 9:577 59 DOI.7/s76--55-6 A packet-reordering solution to wireless losses in transmission control protocol Ka-Cheong Leung Chengdi Lai Victor O. K. Li Daiqin Yang Published online: 6 February
More informationParallel TCP Data Transfers: A Practical Model and its Application
D r a g a n a D a m j a n o v i ć Parallel TCP Data Transfers: A Practical Model and its Application s u b m i t t e d t o the Faculty of Mathematics, Computer Science and Physics, the University of Innsbruck
More informationCS551 End-to-End Internet Packet Dynamics [Paxson99b]
CS551 End-to-End Internet Packet Dynamics [Paxson99b] Bill Cheng http://merlot.usc.edu/cs551-f12 1 End-to-end Packet Dynamics How do you measure Internet performance? Why do people want to know? Are ISPs
More informationICOM 5026-090: Computer Networks Chapter 6: The Transport Layer. By Dr Yi Qian Department of Electronic and Computer Engineering Fall 2006 UPRM
ICOM 5026-090: Computer Networks Chapter 6: The Transport Layer By Dr Yi Qian Department of Electronic and Computer Engineering Fall 2006 Outline The transport service Elements of transport protocols A
More informationLinux 2.4 Implementation of Westwood+ TCP with rate-halving: A Performance Evaluation over the Internet
Linux. Implementation of TCP with rate-halving: A Performance Evaluation over the Internet A. Dell Aera, L. A. Grieco, S. Mascolo Dipartimento di Elettrotecnica ed Elettronica Politecnico di Bari Via Orabona,
More informationEffects of Filler Traffic In IP Networks. Adam Feldman April 5, 2001 Master s Project
Effects of Filler Traffic In IP Networks Adam Feldman April 5, 2001 Master s Project Abstract On the Internet, there is a well-documented requirement that much more bandwidth be available than is used
More informationTCP/IP Performance with Random Loss and Bidirectional Congestion
IEEE/ACM TRANSACTIONS ON NETWORKING, VOL. 8, NO. 5, OCTOBER 2000 541 TCP/IP Performance with Random Loss and Bidirectional Congestion T. V. Lakshman, Senior Member, IEEE, Upamanyu Madhow, Senior Member,
More informationHigh Speed Internet Access Using Satellite-Based DVB Networks
High Speed Internet Access Using Satellite-Based DVB Networks Nihal K. G. Samaraweera and Godred Fairhurst Electronics Research Group, Department of Engineering University of Aberdeen, Aberdeen, AB24 3UE,
More informationSTUDY OF TCP VARIANTS OVER WIRELESS NETWORK
STUDY OF VARIANTS OVER WIRELESS NETWORK 1 DEVENDRA SINGH KUSHWAHA, 2 VIKASH K SINGH, 3 SHAIBYA SINGH, 4 SONAL SHARMA 1,2,3,4 Assistant Professor, Dept. of Computer Science, Indira Gandhi National Tribal
More informationResearch of TCP ssthresh Dynamical Adjustment Algorithm Based on Available Bandwidth in Mixed Networks
Research of TCP ssthresh Dynamical Adjustment Algorithm Based on Available Bandwidth in Mixed Networks 1 Wang Zhanjie, 2 Zhang Yunyang 1, First Author Department of Computer Science,Dalian University of
More informationApplying Router-Assisted Congestion Control to Wireless Networks: Challenges and Solutions 1
Applying Router-Assisted Congestion Control to Wireless Networks: Challenges and Solutions Jian Pu and Mounir Hamdi Department of Computer Science and Engineering, HKUST, Hong Kong {pujian, hamdi}@cse.ust.hk
More informationSIP Server Overload Control: Design and Evaluation
SIP Server Overload Control: Design and Evaluation Charles Shen and Henning Schulzrinne Columbia University Erich Nahum IBM T.J. Watson Research Center Session Initiation Protocol (SIP) Application layer
More informationOptimization of Communication Systems Lecture 6: Internet TCP Congestion Control
Optimization of Communication Systems Lecture 6: Internet TCP Congestion Control Professor M. Chiang Electrical Engineering Department, Princeton University ELE539A February 21, 2007 Lecture Outline TCP
More informationCSE331: Introduction to Networks and Security. Lecture 9 Fall 2006
CSE33: Introduction to Networks and Security Lecture 9 Fall 2006 Announcements Project Due TODAY HW Due on Friday Midterm I will be held next Friday, Oct. 6th. Will cover all course material up to next
More informationHyperIP : VERITAS Replication Application Note
QuickTime and a Graphics decompressor are needed to see this picture. HyperIP : VERITAS Replication Application Note Introduction HyperIP is a Linux software application that quantifiably and measurably
More informationHomework 3 assignment for ECE374 Posted: 03/13/15 Due: 03/27/15
1 Homework 3 assignment for ECE374 Posted: 03/13/15 Due: 03/27/15 Note: In all written assignments, please show as much of your work as you can. Even if you get a wrong answer, you can get partial credit
More informationPerformance evaluation of TCP connections in ideal and non-ideal network environments
Computer Communications 24 2001) 1769±1779 www.elsevier.com/locate/comcom Performance evaluation of TCP connections in ideal and non-ideal network environments Hala ElAarag, Mostafa Bassiouni* School of
More informationPacket Queueing Delay
Some Active Queue Management Methods for Controlling Packet Queueing Delay Mahmud H. Etbega Mohamed, MSc PhD 2009 Design and Performance Evaluation of Some New Versions of Active Queue Management Schemes
More informationAnswer: that dprop equals dtrans. seconds. a) d prop. b) d trans
Chapter 1 1) p. 98: P-6 This elementary problem begins to explore propagation delay and transmission delay, two central concepts in data networking. Consider two hosts, A and B, connected by single link
More informationTCP/IP Optimization for Wide Area Storage Networks. Dr. Joseph L White Juniper Networks
TCP/IP Optimization for Wide Area Storage Networks Dr. Joseph L White Juniper Networks SNIA Legal Notice The material contained in this tutorial is copyrighted by the SNIA. Member companies and individuals
More informationLa couche transport dans l'internet (la suite TCP/IP)
La couche transport dans l'internet (la suite TCP/IP) C. Pham Université de Pau et des Pays de l Adour Département Informatique http://www.univ-pau.fr/~cpham Congduc.Pham@univ-pau.fr Cours de C. Pham,
More informationComputer Networks. Chapter 5 Transport Protocols
Computer Networks Chapter 5 Transport Protocols Transport Protocol Provides end-to-end transport Hides the network details Transport protocol or service (TS) offers: Different types of services QoS Data
More informationDelay, loss, layered architectures. packets queue in router buffers. packets queueing (delay)
Computer Networks Delay, loss and throughput Layered architectures How do loss and delay occur? packets queue in router buffers packet arrival rate to exceeds output capacity packets queue, wait for turn
More informationAdvanced satellite infrastructures in future global Grid computing: network solutions to compensate delivery delay ISTI CNR
Advanced satellite infrastructures in future global Grid computing: network solutions to compensate delivery delay Blasco Bonito, Alberto Gotta and Raffaello Secchi ISTI CNR Outline Introduction Grid Networks
More informationAPPENDIX 1 USER LEVEL IMPLEMENTATION OF PPATPAN IN LINUX SYSTEM
152 APPENDIX 1 USER LEVEL IMPLEMENTATION OF PPATPAN IN LINUX SYSTEM A1.1 INTRODUCTION PPATPAN is implemented in a test bed with five Linux system arranged in a multihop topology. The system is implemented
More informationLecture 8 Performance Measurements and Metrics. Performance Metrics. Outline. Performance Metrics. Performance Metrics Performance Measurements
Outline Lecture 8 Performance Measurements and Metrics Performance Metrics Performance Measurements Kurose-Ross: 1.2-1.4 (Hassan-Jain: Chapter 3 Performance Measurement of TCP/IP Networks ) 2010-02-17
More informationIntroduction. Abusayeed Saifullah. CS 5600 Computer Networks. These slides are adapted from Kurose and Ross
Introduction Abusayeed Saifullah CS 5600 Computer Networks These slides are adapted from Kurose and Ross Roadmap 1.1 what is the Inter? 1.2 work edge end systems, works, links 1.3 work core packet switching,
More informationA Study on TCP Performance over Mobile Ad Hoc Networks
215 A Study on TCP Performance over Mobile Ad Hoc Networks Shweta Sharma 1, Anshika Garg 2 1 School of Computing Science and Engineering, Galgotias University, Greater Noida 2 School of Computing Science
More informationThe Quality of Internet Service: AT&T s Global IP Network Performance Measurements
The Quality of Internet Service: AT&T s Global IP Network Performance Measurements In today's economy, corporations need to make the most of opportunities made possible by the Internet, while managing
More informationThe Data Replication Bottleneck: Overcoming Out of Order and Lost Packets across the WAN
The Data Replication Bottleneck: Overcoming Out of Order and Lost Packets across the WAN By Jim Metzler, Cofounder, Webtorials Editorial/Analyst Division Background and Goal Many papers have been written
More informationReferring to the above question, the end-to-end delay (transmission delay plus propagation delay) is
CS326e Quiz 3 The first correct 10 answers will be worth 1 point each. Each subsequent correct answer will be worth 0.2 points. Circle the correct answer. UTEID In the following 7 problems, we are sending
More informationComputer Networks CS321
Computer Networks CS321 Dr. Ramana I.I.T Jodhpur Dr. Ramana ( I.I.T Jodhpur ) Computer Networks CS321 1 / 22 Outline of the Lectures 1 Introduction OSI Reference Model Internet Protocol Performance Metrics
More informationTTC New Reno - Consistent Control of Packet Traffic
IMPROVE PERFORMANCE OF TCP NEW RENO OVER MOBILE AD-HOC NETWORK USING ABRA Dhananjay Bisen 1 and Sanjeev Sharma 2 1 M.Tech, School Of Information Technology, RGPV, BHOPAL, INDIA 1 bisen.it2007@gmail.com
More informationCOMP 3331/9331: Computer Networks and Applications. Lab Exercise 3: TCP and UDP (Solutions)
COMP 3331/9331: Computer Networks and Applications Lab Exercise 3: TCP and UDP (Solutions) AIM To investigate the behaviour of TCP and UDP in greater detail. EXPERIMENT 1: Understanding TCP Basics Tools
More informationRandom Early Detection Gateways for Congestion Avoidance
Random Early Detection Gateways for Congestion Avoidance Sally Floyd and Van Jacobson Lawrence Berkeley Laboratory University of California floyd@eelblgov van@eelblgov To appear in the August 1993 IEEE/ACM
More informationMultipath TCP under Massive Packet Reordering
Multipath TCP under Massive Packet Reordering Nathan Farrington UC San Diego farrington@cs.ucsd.edu Abstract Conventional wisdom states that TCP performs poorly when packets arrive out of order. Reordered
More information