Transport Layer: UDP vs. TCP

Size: px
Start display at page:

Download "Transport Layer: UDP vs. TCP"

Transcription

1 EEC 189Q: Computer Networks Transport Layer: UDP vs. TCP Reading: 8.4 & 8.5 Review: Internet Protocol Stack Application Telnet FTP HTTP Transport Network Link Physical bits on wire TCP LAN IP UDP Packet radio Do you remember the various mechanisms we have learned at network & link layers? 2 Page 1

2 An Example Protocol Stack View H1 H8 UDP/ TCP R1 R2 R3 UDP/ TCP IP IP IP IP IP ETH ETH FDDI FDDI PPP PPP ETH ETH 3 Problem At what rate do you send data? - What is max useful sending rate for different apps? Two components - Flow control make sure that the receiver can receive sliding-window based flow control: receiver reports window size to sender higher window higher throughput throughput = window/rtt - Congestion control make sure that the network can deliver 4 Page 2

3 Transport Layer Services Underlying best-effort network - drops messages - re-orders messages - delivers duplicate copies of a given message - delivers messages after an arbitrarily long delay Common end-to-end services - guarantee message delivery - deliver messages in the same order they are sent - deliver at most one copy of each message - allow the receiver to flow control the sender - support multiple application processes on each host 5 Data Link vs Transport Potentially connects many different hosts - need explicit connection establishment and termination Potentially different RTT - need adaptive timeout mechanism Potentially long delay in network - need to be prepared for arrival of very old packets Potentially different capacity at destination - need to accommodate different node capacity Potentially different network capacity - need to be prepared for network congestion 6 Page 3

4 Transport Layer: Connectionless Service Goal: data transfer between end systems UDP - User Datagram Protocol - RFC Internet s connectionless service - Unreliable (unordered) data transfer - No flow control - No congestion control 7 User Datagram Protocol (UDP) Adds multiplexing Endpoints identified by ports - servers have well-known ports - see /etc/services on Unix Header format SrcPort DstPort Checksum Length Optional checksum - pseudo header + UDP header + data Data 8 Page 4

5 Transport Layer: Connection-Oriented Service Goal: data transfer between end systems Handshaking: setup (prepare for) data transfer ahead of time - Hello, hello back human protocol - set up state in two communicating hosts TCP - Transmission Control Protocol - RFC 793, 1122, 1323, 2018, Internet s connection-oriented service 9 Transmission Control Protocol (TCP) Point-to -Point - One sender, one receiver Connection Management - Connection oriented: handshaking (exchange of control messages) initialize sender, receiver state before data exchange Reliable, in-order byte-stream data transfer - loss: acknowledgements and retransmissions Flow control: - sender won t overwhelm receiver - Pipelined Congestion control: - senders slow down sending rate when network congested (so sender won t overwhelm network) 10 Page 5

6 Examples App s using TCP: HTTP (Web), FTP (file transfer), Telnet (remote login), SMTP ( ) App s using UDP: Streaming media, teleconferencing, DNS, Internet telephony 11 TCP Overview Byte-stream - App writes bytes - TCP sends segments - App reads bytes Full duplex Send and receive buffer Application process Application process Write bytes Read bytes TCP Send buffer TCP Receive buffer Segment Segment Segment Transmit segments 12 Page 6

7 TCP: Overview (cont d) The TCP connection primitive is known as the socket A socket may be viewed as a bi-directional pipe between two hosts Connecting a socket requires a destination IP address and port number socket door application writes data TCP send buffer application reads data TCP receive buffer socket door segment 13 TCP Ports Ports allow a host to maintain more than one connection to a single host All port number less than 256 are reserved for standard services like: - Telnet - FTP - - News - etc. (See a UNIX /etc/services file for more) 14 Page 7

8 TCP segment structure URG: urgent data (generally not used) ACK: ACK # valid PSH: push data now (generally not used) RST, SYN, FIN: connection estab (setup, teardown commands) Internet checksum (TCP header & IP addr field) head len 32 bits source port # dest port # sequence number acknowledgement number not used UAPR S F checksum Receive window Urg data pnter Options (variable length) application data (variable length) counting by bytes of data (not segments!) # bytes rcvr willing to accept (i.e., # of bytes sender may transmit) 15 TCP Segment Format (cont) Each connection identified with 4-tuple: - (SrcPort, SrcIPAddr, DstPort, DstIPAddr) Sliding window + flow control - acknowledgment, SequenceNum, AdvertisedWinow Data (SequenceNum) Sender Receiver Acknowledgment + AdvertisedWindow Flags - SYN, FIN, RESET, PUSH, URG, ACK Checksum - pseudo header + TCP header + data 16 Page 8

9 TCP Connection Establishment Initialize TCP variables Step 1: Client sends TCP SYN segment to server - specifies initial seq # - no data Step 2: Server receives SYN, replies with SYNACK - server allocates buffers - specifies server initial seq. # Step 3: Client receives SYNACK, replies with ACK, which may contain data Active participant (client) Three-way handshake SYN, SequenceNum = x SYN + ACK, SequenceNum = y, Acknowledgment = x + 1 ACK, Acknowledgment = y + 1 Passive participant (server) 17 TCP Connection Termination Closing a connection: client server Client closes socket: Step 1: client end system sends TCP FINcontrol segment to server Step 2: server receives FIN, replies with ACK. Closes connection, sends FIN. close FIN ACK FIN close timed wait ACK closed 18 Page 9

10 TCP Connection Termination (cont.) Step 3: Client receives FIN, replies with ACK. - Enters timed wait - will respond with ACK to received FINs closing client FIN server Step 4: Server, receives ACK. Connection closed. ACK FIN closing timed wait ACK closed closed 19 TCP Connection Management TCP client lifecycle 20 Page 10

11 TCP Connection Management (cont) TCP server lifecycle 21 TCP Seq. # s and ACKs Seq. # s: Byte stream number of first byte in segment s data ACKs: Seq # of next byte expected from other side - cumulative ACK User types C host ACKs receipt of echoed C Host A Host B Seq=42, ACK=79, data = C Seq=79, ACK=43, data = C Seq=43, ACK=80 host ACKs receipt of C, echoes back C time simple telnet scenario 22 Page 11

12 TCP Flow Control Receive side of TCP connection has a receive buffer: flow control sender won t overflow receiver s buffer by transmitting too much, too fast Speed-matching service: matching the send rate to the receiving app s drain rate App process may be slow at reading from buffer 23 TCP Flow control: how it works (Suppose TCP receiver discards out-of-order segments) spare room in buffer = RcvWindow = RcvBuffer-[LastByteRcvd - LastByteRead] Rcvr advertises spare room by including value of RcvWindow in segments Sender limits unacked data to RcvWindow - guarantees receive buffer doesn t overflow 24 Page 12

13 TCP Flow Control (cont d) Important info. in TCP/IP packet headers Contained in TCP header Contained in IP header Send N SEQ Number of byes in packet (N) Sequence # of first data byte in packet (SEQ) Recv ACK WIN ACK bit Set Sequence # of next expected byte (ACK) Window Size at the receiver (WIN) Contained in TCP header 25 TCP Flow Control: Illustration Sender Receiver Application Receiver s buffer does a 2K 0 4K write 2K SEQ=0 Empty Application does a 2K write Sender is blocked ACK=2048 WIN=2048 2K SEQ=2048 ACK=4096 WIN=0 ACK=4096 WIN=2048 2K 4K Application reads 2K 2K Sender may send up to 2K time 26 Page 13

14 Piggybacking ACK Piggybacking - Allows more efficient bidirectional communication Data fromack for data A to B from B to A N SEQ ACK WIN A B N SEQ ACK WIN Data from B to A ACK for data from A to B 27 TCP: Retransmission Scenarios Host A Host B Host A Host B timeout Seq=92, 8 bytes data X loss ACK=100 Seq=92, 8 bytes data Seq=100 timeout Seq=92 timeout Seq=92, 8 bytes data Seq=100, 20 bytes data ACK=100 ACK=120 Seq=92, 8 bytes data ACK=100 ACK=120 time lost ACK scenario time premature timeout, cumulative ACKs 28 Page 14

15 TCP Round Trip Time and Timeout Q: how to set TCP timeout value? Longer than RTT - note: RTT will vary Too short: premature timeout - unnecessary retransmissions Too long: slow reaction to segment loss Q: how to estimate RTT? SampleRTT: measured time from segment transmission until ACK receipt SampleRTT will vary, want estimated RTT smoother - use several recent measurements, not just current SampleRTT 29 Adaptive Retransmission (Original Algorithm) Measure SampleRTT for each segment/ ACK pair Compute weighted average of RTT - EstRTT = α xestimatedrtt + (1-α) xsamplertt α between 0.8 and Exponential weighted moving average - Influence of past sample decreases exponentially fast Set timeout based on EstRTT - TimeOut =2xEstRTT 30 Page 15

16 Example RTT estimation: 350 RTT: gaia.cs.umass.edu to fantasia.eurecom.fr RTT (milliseconds) Time (seconds) SampleRTT Estimated RTT 31 Karn/Partridge Algorithm Sender Receiver Sender Receiver Original transmission Original transmission SampleR TT Retransmission ACK SampleR TT ACK Retransmission Do not sample RTT when retransmitting Double timeout after each retransmission 32 Page 16

17 Jacobson/ Karels Algorithm New Calculations for average RTT - Diff = samplertt -EstRTT - EstRTT = EstRTT + ( d x Diff) - Dev = Dev + d ( Diff - Dev) where d is a fraction between 0 and 1 Consider variance when setting timeout value - TimeOut = µ xestrtt + φ xdev where µ = 1 and φ= 4 33 Page 17

Data Communication & Networks G22.2262-001. Session 9 - Main Theme The Internet Transport Protocols: TCP, UDP. Dr. Jean-Claude Franchitti

Data Communication & Networks G22.2262-001. Session 9 - Main Theme The Internet Transport Protocols: TCP, UDP. Dr. Jean-Claude Franchitti Data Communication & Networks G22.2262-001 Session 9 - Main Theme The Internet Transport Protocols: TCP, UDP Dr. Jean-Claude Franchitti New York University Computer Science Department Courant Institute

More information

Transport Layer Outline

Transport Layer Outline Transport Layer Outline 3.1 Transport-layer services 3.2 Multiplexing and demultiplexing 3.3 Connectionless transport: UDP 3.4 Principles of reliable data transfer 3.5 Connection-oriented transport: TCP

More information

Computer Networking. TCP: Overview RFCs: 793, 1122, 1323, 2018, 2581

Computer Networking. TCP: Overview RFCs: 793, 1122, 1323, 2018, 2581 Computer Networking Connec1on- Oriented Transport: : Overview RFCs: 793, 1122, 1323, 2018, 2581 point- to- point: one sender, one receiver reliable, in- order byte steam: no message boundaries pipelined:

More information

RSC Part III: Transport Layer 3. TCP

RSC Part III: Transport Layer 3. TCP RSC Part III: Transport Layer 3. TCP Redes y Servicios de Comunicaciones Universidad Carlos III de Madrid These slides are, mainly, part of the companion slides to the book Computer Networking: A Top Down

More information

CSCE 463/612 Networks and Distributed Processing Spring 2016

CSCE 463/612 Networks and Distributed Processing Spring 2016 CSCE 463/612 Networks and Distributed Processing Spring 2016 Transport Layer IV Dmitri Loguinov Texas A&M University March 10, 2016 Original slides copyright 1996-2004 J.F Kurose and K.W. Ross 1 Chapter

More information

TCP: Overview RFCs: 793, 1122, 1323, 2018, 2581

TCP: Overview RFCs: 793, 1122, 1323, 2018, 2581 TCP: Overview RFCs: 793, 1122, 1323, 2018, 2581 socket door point-to-point: one sender, one receiver reliable, in-order byte steam: no message boundaries pipelined: TCP congestion and flow control set

More information

TCP (Transmission Control Protocol)

TCP (Transmission Control Protocol) TCP (Transmission Control Protocol) Originally defined in RFC 793 (September 1981) UDP features: multiplexing + protection against bit errors Ports, checksum Connection-oriented Establishment and teardown

More information

Chapter 3 Transport Layer

Chapter 3 Transport Layer Chapter 3 Transport Layer All material copyright 1996-2009 J.F Kurose and K.W. Ross, All Rights Reserved Computer Networking: A Top Down Approach 5 th edition. Jim Kurose, Keith Ross Addison-Wesley, April

More information

Transport Layer. Transport Protocols. Transport Layer Services. Transport Services and Protocols. Transport vs. Application and Network Layer

Transport Layer. Transport Protocols. Transport Layer Services. Transport Services and Protocols. Transport vs. Application and Network Layer Transport Layer Transport Layer Services connection-oriented vs. connectionless multiplexing and demultplexing UDP: Connectionless Unreliable Service TCP: Connection-Oriented Reliable Service connection

More information

Overview of TCP. Overview of TCP. Overview of TCP. Overview of TCP. Connection-oriented, byte-stream

Overview of TCP. Overview of TCP. Overview of TCP. Overview of TCP. Connection-oriented, byte-stream Overview of TCP Overview of TCP Connection-oriented, byte-stream sending process writes some number of bytes TCP breaks into segments and sends via IP receiving process reads some number of bytes Full

More information

Transport Control Protocol (TCP)

Transport Control Protocol (TCP) Transport Control Protocol (TCP) Richard T. B. Ma School of Computing National University of Singapore CS 3103: Compute Networks and Protocols Transport services and protocols provide logical communication

More information

Transport Layer Protocols

Transport 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 information

application reads data socket door TCP receive buffer 32 bits source port # dest port # sequence number acknowledgement number not used checksum

application reads data socket door TCP receive buffer 32 bits source port # dest port # sequence number acknowledgement number not used checksum socket door TCP: Overview RFCs: 793, 1122, 1323, 2018, 2581 point-to-point: one sender, one receiver reliable, in-order, byte steam: no message boundaries pipelined: TCP congestion and flow control set

More information

CS640: Introduction to Computer Networks. Transport Protocols. Functionality Split

CS640: Introduction to Computer Networks. Transport Protocols. Functionality Split CS640: Introduction to Computer Networks Aditya Akella Lecture 14 TCP I - Transport Protocols: TCP Segments, Flow control and Connection Setup Transport Protocols Lowest level endto-end protocol. Header

More information

Transmission Control Protocol (TCP) A brief summary

Transmission Control Protocol (TCP) A brief summary Transmission Control Protocol (TCP) A brief summary TCP Basics TCP (RFC 793) is a connection-oriented transport protocol TCP entities only present at hosts (end-end) retain state of each open connection

More information

Livello di trasporto TCP

Livello di trasporto TCP Livello di trasporto TCP TCP: Overview RFCs: 793, 1122, 1323, 2018, 2581 point-to-point: one sender, one receiver reliable, in-order byte stream: pipelined: no message boundaries TCP congestion and flow

More information

Internet Transport Protocols

Internet Transport Protocols Internet Transport Protocols Transmission Control Protocol (TCP): TCP Socket Primitives. The TCP Segment Header. Establishing & Terminating TCP Connections: TCP Three-way Handshake. TCP Connection Management

More information

TCP. Raj Jain. Professor of CIS The Ohio State University Columbus, OH 43210 Raj Jain 20-1

TCP. Raj Jain. Professor of CIS The Ohio State University Columbus, OH 43210  Raj Jain 20-1 TCP Professor of CIS Columbus, OH 43210 Jain@ACM.Org http://www.cis.ohio-state.edu/~jain/ 20-1 Overview Key features, Header format Mechanisms, Implementation choices Slow start congestion avoidance, Fast

More information

Outline. Lecture 4: TCP TCP TCP. TCP Segment. How TCP Provides Reliability. Internetworking. TCP Transmission Control Protocol.

Outline. Lecture 4: TCP TCP TCP. TCP Segment. How TCP Provides Reliability. Internetworking. TCP Transmission Control Protocol. Internetworking Outline TCP Transmission Control Protocol RFC 793 (and several follow-ups) Literature: Lecture 4: TCP Forouzan, TCP/IP Protocol Suite: Ch 12 Connection Management Reliability Flow control

More information

TCP context and interfaces

TCP context and interfaces Linux Networking: tcp David Morgan TCP context and interfaces Computer A Computer B application process application process data data data data TCP process TCP process a network 1 TCP purposes and features

More information

Lecture 3: The Transport Layer: UDP and TCP

Lecture 3: The Transport Layer: UDP and TCP Lecture 3: The Transport Layer: UDP and TCP Prof. Shervin Shirmohammadi SITE, University of Ottawa Prof. Shervin Shirmohammadi CEG 4185 3-1 The Transport Layer Provides efficient and robust end-to-end

More information

- TCP and UDP - Transport Layer Protocols

- TCP and UDP - Transport Layer Protocols 1 Transport Layer Protocols - TCP and UDP - The Transport layer (OSI Layer-4) does not actually transport data, despite its name. Instead, this layer is responsible for the reliable transfer of data, by

More information

The Transmission Control Protocol (TCP): Lecture 1

The Transmission Control Protocol (TCP): Lecture 1 Today s Lecture The Transmission Control Protocol (TCP): Lecture 1 I. TCP overview II. The TCP Header III. Connection establishment and termination Internet Protocols CSC / ECE 573 Fall, 2005 N. C. State

More information

Computer Networks. Chapter 5 Transport Protocols

Computer 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 information

TCP and UDP. Raj Jain. Professor of CIS The Ohio State University Columbus, OH

TCP and UDP. Raj Jain. Professor of CIS The Ohio State University Columbus, OH TCP and UDP Professor of CIS Columbus, OH 43210 Jain@ACM.Org http://www.cis.ohio-state.edu/~jain/ 12-1 Overview Key features Header format Mechanisms Implementation choices Slow start congestion avoidance

More information

Computer Systems: TCP - Adaptive Distributed Reliable Transport Protocol

Computer Systems: TCP - Adaptive Distributed Reliable Transport Protocol Computer Systems: TCP - Adaptive Distributed Reliable Transport Protocol Presenter: Sandeep K. S. Gupta Reference: -- Chapter 3, 5 Computer Networking, Kurose and Ross, Addison Wesley - Chapter 7, An Engineering

More information

Slides from TCP/IP - Forouzan. Chapter 12 TCP

Slides from TCP/IP - Forouzan. Chapter 12 TCP Chapter 12 Services Segments and Options Flow Control and Error Control rs Connections State Transition Diagram Congestion Control Operation and Design Figure Application layer Position of in /IP protocol

More information

Transports and TCP. Adolfo Rodriguez CPS 214

Transports and TCP. Adolfo Rodriguez CPS 214 Transports and TCP Adolfo Rodriguez CPS 214 Host-to to-host vs. Process-to to-process Communication Until now, we have focused on delivering packets between arbitrary hosts connected to Internet Routing

More information

Lecture 19 Overview. Last Lecture. This Lecture. Next Lecture. Internet Protocol (2) Transport Control Protocol (1) Source: chapters 23, 24

Lecture 19 Overview. Last Lecture. This Lecture. Next Lecture. Internet Protocol (2) Transport Control Protocol (1) Source: chapters 23, 24 Lecture 19 Overview Last Lecture Internet Protocol (2) This Lecture Transport Control Protocol (1) Generic transport layer Connection management Source: chapters 23, 24 Next Lecture Transport Control Protocol

More information

Transport Layer. Abusayeed Saifullah. CS 5600 Computer Networks. These slides are adapted from Kurose and Ross

Transport Layer. Abusayeed Saifullah. CS 5600 Computer Networks. These slides are adapted from Kurose and Ross Transport Layer Abusayeed Saifullah CS 5600 Computer Networks These slides are adapted from Kurose and Ross Transport Layer our goals: v understand principles behind transport layer services: multiplexing,

More information

CIS 551 / TCOM 401 Computer and Network Security

CIS 551 / TCOM 401 Computer and Network Security CIS 551 / TCOM 401 Computer and Network Security Spring 2008 Lecture 11 2/26/08 CIS/TCOM 551 1 Wireless (802.11) Spread spectrum radio 2.4GHz frequency band Bandwidth ranges 1, 2, 5.5, 11, 22, 54, 248

More information

Transportation Protocols: UDP, TCP & RTP

Transportation Protocols: UDP, TCP & RTP Transportation Protocols: UDP, TCP & RTP Transportation Functions UDP (User Datagram Protocol) Port Number to Identify Different Applications Server and Client as well as Port TCP (Transmission Control

More information

TCP: Reliable, In-Order Delivery

TCP: Reliable, In-Order Delivery TCP: Reliable, In-Order Delivery EE 122: Intro to Communication Networks Fall 2006 (MW 4-5:30 in Donner 155) Vern Paxson TAs: Dilip Antony Joseph and Sukun Kim http://inst.eecs.berkeley.edu/~ee122/ Materials

More information

Process-to. to-process Communication. Transports and TCP. A Brief Internet History UDP. TCP Timeline. TCP: After 1990

Process-to. to-process Communication. Transports and TCP. A Brief Internet History UDP. TCP Timeline. TCP: After 1990 Transports and TCP Adolfo Rodriguez CPS 214 Host-to to-host vs. Process-to to-process Communication Until now, we have focused on delivering packets between arbitrary hosts connected to Internet Routing

More information

q Connection establishment (if connection-oriented) q Data transfer q Connection release (if conn-oriented) q Addressing the transport user

q Connection establishment (if connection-oriented) q Data transfer q Connection release (if conn-oriented) q Addressing the transport user Transport service characterization The Transport Layer End-to-End Protocols: UDP and TCP Connection establishment (if connection-oriented) Data transfer Reliable ( TCP) Unreliable / best effort ( UDP)

More information

Module 11: TCP/IP Transport and Application Layers

Module 11: TCP/IP Transport and Application Layers Module 11: TCP/IP Transport and Application Layers 11.1 TCP/IP Transport Layer 11.1.1 Introduction to the TCP/IP transport layer The primary duties of the transport layer are to transport and regulate

More information

Transport Layer INF3190 / INF4190. Foreleser: Carsten Griwodz

Transport Layer INF3190 / INF4190. Foreleser: Carsten Griwodz Transport Layer INF3190 / INF4190 Foreleser: Carsten Griwodz Email: griff@ifi.uio.no Transport layer Flow Control: Generic approaches Flow Control on Transport Layer Fast sender shall not flood slow receiver

More information

TCP - Part I. Relates to Lab 5. First module on TCP which covers packet format, data transfer, and connection management.

TCP - Part I. Relates to Lab 5. First module on TCP which covers packet format, data transfer, and connection management. TCP - Part I Relates to Lab 5. First module on TCP which covers packet format, data transfer, and connection management. 1 Overview TCP = Transmission Control Protocol Connection-oriented protocol Provides

More information

TCP transmission control protocol

TCP transmission control protocol TCP transmission control protocol Suguru Yamaguchi 2014 Information Network 1 Functions that transport layer provides! Model: inter-process communication Identification of process Communication pair of

More information

Chapter 15. Transmission Control Protocol (TCP) TCP/IP Protocol Suite 1

Chapter 15. Transmission Control Protocol (TCP) TCP/IP Protocol Suite 1 Chapter 15 Transmission Control Protocol (TCP) TCP/IP Protocol Suite 1 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter Outline TCP/IP Protocol Suite 2

More information

Chapter 5. Transport layer protocols

Chapter 5. Transport layer protocols Chapter 5. Transport layer protocols This chapter provides an overview of the most important and common protocols of the TCP/IP transport layer. These include: User Datagram Protocol (UDP) Transmission

More information

Guide to TCP/IP, Third Edition. Chapter 5: Transport Layer TCP/IP Protocols

Guide to TCP/IP, Third Edition. Chapter 5: Transport Layer TCP/IP Protocols Guide to TCP/IP, Third Edition Chapter 5: Transport Layer TCP/IP Protocols Objectives Understand the key features and functions of the User Datagram Protocol Explain the mechanisms that drive segmentation,

More information

Chapter 15. Transmission Control Protocol (TCP) TCP/IP Protocol Suite 1

Chapter 15. Transmission Control Protocol (TCP) TCP/IP Protocol Suite 1 Chapter 15 Transmission Control Protocol (TCP) TCP/IP Protocol Suite 1 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. OBJECTIVES: To introduce TCP as a protocol

More information

I. Internet Control Message Protocol (ICMP) Week 10

I. Internet Control Message Protocol (ICMP) Week 10 I. Internet Control Message Protocol (ICMP) Week 10 described in RFC 792 helper protocol for IP, but more like a 3 ½ layer protocol (like ARP as a 2 ½ layer protocol) since a helper protocol for IP, uses

More information

TCP: Transmission Control Protocol RFC 793,1122,1223. Prof. Lin Weiguo Copyleft 2009~2015, College of Computing, CUC

TCP: Transmission Control Protocol RFC 793,1122,1223. Prof. Lin Weiguo Copyleft 2009~2015, College of Computing, CUC TCP: Transmission Control Protocol RFC 793,1122,1223 Prof. Lin Weiguo Copyleft 2009~2015, College of Computing, CUC Nov. 2015 TCP/IP Protocol Stack Application Layer FTP, Telnet, HTTP, Transport Layer

More information

Guide to TCP/IP Fourth Edition. Chapter 9: TCP/IP Transport Layer Protocols

Guide to TCP/IP Fourth Edition. Chapter 9: TCP/IP Transport Layer Protocols Guide to TCP/IP Fourth Edition Chapter 9: TCP/IP Transport Layer Protocols Objectives Explain the key features and functions of the User Datagram Protocol and the Transmission Control Protocol Explain,

More information

ICOM 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 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 information

Internet Protocol Stack. TCP: Transmission Control Protocol

Internet Protocol Stack. TCP: Transmission Control Protocol Internet Protocol tack application: supporting network applications HTTP, MTP, FTP, etc transport: endhost-endhost data transfer TCP, UP network: routing of datagrams from source to destination IP, routing

More information

TCP Service Model. Announcements. TCP: Reliable, In-Order Delivery. Today s Lecture. TCP Header. TCP Support for Reliable Delivery

TCP Service Model. Announcements. TCP: Reliable, In-Order Delivery. Today s Lecture. TCP Header. TCP Support for Reliable Delivery Announcements Sukun is away this week. Dilip will cover his section and office hours. TCP: Reliable, In-Order Delivery EE 122: Intro to Communication Networks Fall 2006 (MW 4-5:30 in Donner 155) Vern Paxson

More information

Chapter 1: Introduction. Chapter 1: roadmap. Our goal: Overview:

Chapter 1: Introduction. Chapter 1: roadmap. Our goal: Overview: Chapter 1: Introduction Our goal: get feel and terminology more depth, detail later in course approach: use Internet as example Overview: what s the Internet what s a protocol? network edge network core

More information

TCP/IP and OSI model. TCP/IP Protocol (2) B.2

TCP/IP and OSI model. TCP/IP Protocol (2) B.2 TCP/IP Protocol TCP/IP Transmission Control Protocol/Internetworking Protocol (TCP/IP) standard for the Internet five layers = physical = data link = network = transport = application B.1 TCP/IP and OSI

More information

TCP/IP Concepts Review. Ed Crowley

TCP/IP Concepts Review. Ed Crowley TCP/IP Concepts Review Ed Crowley 1 Objectives At the end of this unit, you will be able to: Describe the TCP/IP protocol stack For each level, explain roles and vulnerabilities Explain basic IP addressing

More information

TCP/IP Tutorial. Transmission Control Protocol Internet Protocol

TCP/IP Tutorial. Transmission Control Protocol Internet Protocol TCP/IP Tutorial Transmission Control Protocol Internet Protocol 1 TCP/IP & OSI In OSI reference model terminology -the TCP/IP protocol suite covers the network and transport layers. TCP/IP can be used

More information

Lecture 6: Congestion Control

Lecture 6: Congestion Control Lecture 6: Congestion Control Overview Internet is a network of networks Narrow waist of IP: unreliable, best-effort datagram delivery Packet forwarding: input port to output port Routing protocols: computing

More information

TCP "Real" Reliable Transport

TCP Real Reliable Transport TCP "Real" Reliable Transport CS 356 University of Texas at Austin Dr. David A. Bryan VERY SIGNIFICANT content used or adapted from Computer Networking: A Top- Down Approach, 6e, Kurose and Ross, Addisson-

More information

Computer Networks UDP and TCP

Computer Networks UDP and TCP Computer Networks UDP and TCP Saad Mneimneh Computer Science Hunter College of CUNY New York I m a system programmer specializing in TCP/IP communication protocol on UNIX systems. How can I explain a thing

More information

Due for Week Group of 3 (max) Percentage awarded for comments, coding practice, layout style, naming convention, completed task.

Due for Week Group of 3 (max) Percentage awarded for comments, coding practice, layout style, naming convention, completed task. EE4607 Project Goals Details Due for Week 11-12. Group of 3 (max) Percentage awarded for comments, coding practice, layout style, naming convention, completed task. Task Create a SDL implementation of

More information

The following reference answers are based on the trace files provided with the text book, which can be downloaded from the textbook website.

The following reference answers are based on the trace files provided with the text book, which can be downloaded from the textbook website. Wireshark Lab 3 TCP The following reference answers are based on the trace files provided with the text book, which can be downloaded from the textbook website. TCP Basics Answer the following questions

More information

CS 421: Computer Networks FALL MIDTERM I November 22, minutes

CS 421: Computer Networks FALL MIDTERM I November 22, minutes CS 421: Computer Networks FALL 2004 MIDTERM I November 22, 2004 120 minutes Name: Student No: Show all your work very clearly. Partial credits will only be given if you carefully state your answer with

More information

CHAPTER 24. Questions PRACTICE SET

CHAPTER 24. Questions PRACTICE SET CHAPTER 24 PRACTICE SET Questions Q24-1. The protocol field of the datagram defines the transport-layer protocol that should receive the transport-layer packet. If the value is 06, the protocol is TCP;

More information

TCP - Introduction. Features of TCP

TCP - Introduction. Features of TCP TCP - Introduction The Internet Protocol (IP) provides unreliable datagram service between hosts The Transmission Control Protocol (TCP) provides reliable data delivery It uses IP for datagram delivery

More information

Administrivia CSC458. Sliding Windows, ARQ Connections. This Time. Last Time

Administrivia CSC458. Sliding Windows, ARQ Connections. This Time. Last Time CSC458 Sliding Windows, ARQ Connections Administrivia Projects Project #3 due on Wednesday at 2pm Project #4 out today -- last project Homework Homework #4 out last week, due in two weeks This is our last

More information

Topics. Computer Networks. Introduction. Transport Entity. Quality of Service. Transport Protocol

Topics. Computer Networks. Introduction. Transport Entity. Quality of Service. Transport Protocol Topics Introduction (6.1) Connection Issues (6. - 6..3) TCP (6.4) Computer Networks Transport Layer Introduction Efficient, reliable and cost-effective service to users (application layer) despite limitations

More information

Names & Addresses. Names & Addresses. Hop-by-Hop Packet Forwarding. Longest-Prefix-Match Forwarding. Longest-Prefix-Match Forwarding

Names & Addresses. Names & Addresses. Hop-by-Hop Packet Forwarding. Longest-Prefix-Match Forwarding. Longest-Prefix-Match Forwarding Names & Addresses EE 122: IP Forwarding and Transport Protocols Scott Shenker http://inst.eecs.berkeley.edu/~ee122/ (Materials with thanks to Vern Paxson, Jennifer Rexford, and colleagues at UC Berkeley)

More information

Lab 3. According to above figure, the client computer (source) s IP address is and the TPC port number is 1161.

Lab 3. According to above figure, the client computer (source) s IP address is and the TPC port number is 1161. Lab 3 1. What is the IP address and TCP port number used by the client computer (source) that is transferring the file to gaia.cs.umass.edu? To answer this question, it s probably easiest to select an

More information

Higher Layer Protocols: UDP, TCP, ATM, MPLS

Higher Layer Protocols: UDP, TCP, ATM, MPLS Higher Layer Protocols: UDP, TCP, ATM, MPLS Massachusetts Institute of Technology Slide 1 The TCP/IP Protocol Suite Transmission Control Protocol / Internet Protocol Developed by DARPA to connect Universities

More information

Internet Protocol (IP)

Internet Protocol (IP) TCP/IP CIS 218/238 Internet Protocol (IP) The Internet Protocol (IP) is responsible for ensuring that data is transferred between two Intenret hosts based on a 32 bit address. To be ROUTABLE, a protocol

More information

Chapter 5 TCP Sliding Window. Networking CS 3470, Section 1

Chapter 5 TCP Sliding Window. Networking CS 3470, Section 1 Chapter 5 TCP Sliding Window Networking CS 3470, Section 1 Sliding Window Remember this? What was it useful for? Sliding Window Revisited TCP s variant of the sliding window algorithm, which serves several

More information

COMP 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) 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 information

[Prof. Rupesh G Vaishnav] Page 1

[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 information

B-2 Analyzing TCP/IP Networks with Wireshark. Ray Tompkins Founder of Gearbit www.gearbit.com

B-2 Analyzing TCP/IP Networks with Wireshark. Ray Tompkins Founder of Gearbit www.gearbit.com B-2 Analyzing TCP/IP Networks with Wireshark June 15, 2010 Ray Tompkins Founder of Gearbit www.gearbit.com SHARKFEST 10 Stanford University June 14-17, 2010 TCP In this session we will examine the details

More information

Ethernet. Ethernet. Network Devices

Ethernet. Ethernet. Network Devices Ethernet Babak Kia Adjunct Professor Boston University College of Engineering ENG SC757 - Advanced Microprocessor Design Ethernet Ethernet is a term used to refer to a diverse set of frame based networking

More information

Good Ideas So Far Computer Networking. Outline. Sequence Number Space. Lecture 18 More TCP & Congestion Control. The devilish details of TCP

Good Ideas So Far Computer Networking. Outline. Sequence Number Space. Lecture 18 More TCP & Congestion Control. The devilish details of TCP Good Ideas So Far 15-441 Computer Networking Lecture 18 More TCP & Congestion Control Flow control Stop & wait Parallel stop & wait Sliding window (e.g., advertised windows) Loss recovery outs Acknowledgement-driven

More information

INTERNET PROTOCOLS. Transmission Control Protocol TCP. TCP Services. Stream Deliver Service. Sending and Receiving Buffers. Bytes and Segments

INTERNET PROTOCOLS. Transmission Control Protocol TCP. TCP Services. Stream Deliver Service. Sending and Receiving Buffers. Bytes and Segments INTERNET PROTOCOLS http://www.tutorialspoint.com/internet_technologies/internet_protocols.htm Copyright tutorialspoint.com Transmission Control Protocol TCP TCP is a connection oriented protocol and offers

More information

TCP/IP Concepts Review. A CEH Perspective

TCP/IP Concepts Review. A CEH Perspective TCP/IP Concepts Review A CEH Perspective 1 Objectives At the end of this unit, you will be able to: Describe the TCP/IP protocol stack For each level, explain roles and vulnerabilities Explain basic IP

More information

TCP/IP Concepts Review. A CEH Perspective

TCP/IP Concepts Review. A CEH Perspective TCP/IP Concepts Review A CEH Perspective 1 Objectives At the end of this unit, you will be able to: Describe the TCP/IP protocol stack For each level, explain roles and vulnerabilities Explain basic IP

More information

Hands-On Ethical Hacking and Network Defense - Second Edition. Chapter 2 - TCP/IP Concepts Review

Hands-On Ethical Hacking and Network Defense - Second Edition. Chapter 2 - TCP/IP Concepts Review Objectives After reading this chapter and completing the exercises, you will be able to: Overview of TCP/IP Describe the TCP/IP protocol stack Explain the basic concepts of IP addressing Explain the binary,

More information

CS 268: Lecture 5 (TCP/IP Architecture)

CS 268: Lecture 5 (TCP/IP Architecture) CS 268: Lecture 5 (TCP/IP Architecture) Ion Stoica February 1, 2006 The Problem Before Internet: different packet-switching networks (e.g., ARPANET, ARPA packet radio) - only nodes on the same network

More information

Overview. Lecture 4: Congestion Control TCP. Transport. A Bit of History TCP. Internet is a network of networks

Overview. Lecture 4: Congestion Control TCP. Transport. A Bit of History TCP. Internet is a network of networks Overview Internet is a network of networks Lecture 4: Congestion Control Narrow waist of IP: unreliable, best-effort datagram delivery Packet forwarding: input port to output port Routing protocols: computing

More information

TCP/IP Revisited. IP s Transport Layer UDP and TCP. Computer Science 742 S2C, 2010 TCP UDP

TCP/IP Revisited. IP s Transport Layer UDP and TCP. Computer Science 742 S2C, 2010 TCP UDP TCP/IP, COMPSCI 742, 2010 p. 3/29 IP s Transport Layer UDP and TCP TCP/IP, COMPSCI 742, 2010 p. 4/29 TCP/IP Revisited Computer Science 742 S2C, 2010 Nevil Brownlee, with acknowledgements to Ulrich Speidel

More information

TCP/IP. IPv4 packet layout. IPv4 packet layout. Emin Gun Sirer

TCP/IP. IPv4 packet layout. IPv4 packet layout. Emin Gun Sirer IP TCP/IP Emin Gun Sirer Internetworking protocol Network layer Common packet format for the Internet Specifies what packets look like Fragments long packets into shorter packets Reassembles fragments

More information

Architecture and Performance of the Internet

Architecture and Performance of the Internet SC250 Computer Networking I Architecture and Performance of the Internet Prof. Matthias Grossglauser School of Computer and Communication Sciences EPFL http://lcawww.epfl.ch 1 Today's Objectives Understanding

More information

By: Chunyan Fu, PhD, Ericsson Canada

By: Chunyan Fu, PhD, Ericsson Canada TCP/UDP Basics By: Chunyan Fu, PhD, Ericsson Canada Internet Model Application TCP/UDP IP Link layer Physical layer Transport Service Overview Provide service to application layer by using the service

More information

Transport Layer. Chapter 3.4. Think about

Transport Layer. Chapter 3.4. Think about Chapter 3.4 La 4 Transport La 1 Think about 2 How do MAC addresses differ from that of the network la? What is flat and what is hierarchical addressing? Who defines the IP Address of a device? What is

More information

La couche transport dans l'internet (la suite TCP/IP)

La 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 information

IP Network Layer. Datagram ID FLAG Fragment Offset. IP Datagrams. IP Addresses. IP Addresses. CSCE 515: Computer Network Programming TCP/IP

IP Network Layer. Datagram ID FLAG Fragment Offset. IP Datagrams. IP Addresses. IP Addresses. CSCE 515: Computer Network Programming TCP/IP CSCE 515: Computer Network Programming TCP/IP IP Network Layer Wenyuan Xu Department of Computer Science and Engineering University of South Carolina IP Datagrams IP is the network layer packet delivery

More information

TCP Header - Sequence Number

TCP Header - Sequence Number Introduction to TCP RFC 793 (+ RFC1122) (+ others) Transmission Control Protocol The Transmission Control Protocol (TCP) is intended for use as a highly reliable host-to-host protocol between hosts in

More information

TCP/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 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 information

Transport Layer and Data Center TCP

Transport Layer and Data Center TCP Transport Layer and Data Center TCP Hakim Weatherspoon Assistant Professor, Dept of Computer Science CS 5413: High Performance Systems and Networking September 5, 2014 Slides used and adapted judiciously

More information

Outline. TCP connection setup/data transfer. 15-441 Computer Networking. TCP Reliability. Congestion sources and collapse. Congestion control basics

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 information

Review for Chapter 3

Review for Chapter 3 Review for Chapter 3 R3.Describle why an application developer might choose to run an application over UDP rather than TCP. Answer: An application developer may not want its application to use TCP s congestion

More information

Networking Overview. (as usual, thanks to Dave Wagner and Vern Paxson)

Networking Overview. (as usual, thanks to Dave Wagner and Vern Paxson) Networking Overview (as usual, thanks to Dave Wagner and Vern Paxson) Focus For This Lecture Sufficient background in networking to then explore security issues in next few lectures Networking = the Internet

More information

6.263/16.37: Lectures 3 & 4. The Data Link Layer: ARQ Protocols

6.263/16.37: Lectures 3 & 4. The Data Link Layer: ARQ Protocols 6.263/16.37: Lectures 3 & 4 The Data Link Layer: ARQ Protocols MIT 1 Automatic Repeat ReQuest (ARQ) When the receiver detects errors in a packet, how does it let the transmitter know to re-send the corresponding

More information

Network Security TCP/IP Refresher

Network Security TCP/IP Refresher Network Security TCP/IP Refresher What you (at least) need to know about networking! Dr. David Barrera Network Security HS 2014 Outline Network Reference Models Local Area Networks Internet Protocol (IP)

More information

Introduction to Networking S Y STEMS

Introduction to Networking S Y STEMS Introduction to Networking CS 40: INTRODUCTION TO U NIX A ND L I NUX O P E R AT ING S Y STEMS Objectives Introduce networking, including what it is and what it contains, which includes: Networking layers

More information

Understand the OSI Model

Understand the OSI Model Understand the OSI Model Part 2 Lesson Overview In this lesson, you will learn information about: Frames Packets Segments TCP TCP/IP Model Well-known ports for most-used purposes Anticipatory Set Review

More information

Overview of TCP/IP. TCP/IP and Internet

Overview of TCP/IP. TCP/IP and Internet Overview of TCP/IP System Administrators and network administrators Why networking - communication Why TCP/IP Provides interoperable communications between all types of hardware and all kinds of operating

More information

Objectives of Lecture. Network Architecture. Protocols. Contents

Objectives of Lecture. Network Architecture. Protocols. Contents Objectives of Lecture Network Architecture Show how network architecture can be understood using a layered approach. Introduce the OSI seven layer reference model. Introduce the concepts of internetworking

More information

Fall & Walrand Lecture 22. n A > Seq k, SYN > B. n A <--- Seq j, ACK k+1, SYN+ACK <-- B

Fall & Walrand Lecture 22. n A > Seq k, SYN > B. n A <--- Seq j, ACK k+1, SYN+ACK <-- B Steady State Operation, Lecture 22 Kevin Fall kfall@cs.berkeley.edu Jean Walrand wlr@eecs.berkeley.edu Typical operation looks like this: Seq CK Win Seq CK Win - Fall & Walrand 783 TCP Sequence Numbers

More information

Introduction to TCP/IP

Introduction to TCP/IP Introduction to TCP/IP Raj Jain The Ohio State University Columbus, OH 43210 Nayna Networks Milpitas, CA 95035 Email: Jain@ACM.Org http://www.cis.ohio-state.edu/~jain/ 1 Overview! Internetworking Protocol

More information