Chapter 15. Transmission Control Protocol (TCP) TCP/IP Protocol Suite 1
|
|
|
- Willis Homer Kennedy
- 9 years ago
- Views:
Transcription
1 Chapter 15 Transmission Control Protocol (TCP) TCP/IP Protocol Suite 1 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
2 Chapter Outline TCP/IP Protocol Suite 2
3 15-1 TCP SERVICES Figure 15.1 shows the relationship of TCP to the other protocols in the TCP/IP protocol suite. TCP lies between the application layer and the network layer, and serves as the intermediary between the application programs and the network operations. TCP/IP Protocol Suite 3
4 TCP Services Process-to-Process Communication TCP/IP Protocol Suite 4
5 TCP/IP Protocol Suite 5
6 TCP Services Process-to-Process Communication Stream-oriented Service UDP send messages with predefined boundaries TCP deliver and receive data as a stream of bytes TCP/IP Protocol Suite 6
7 Figure 15.2 Stream delivery TCP/IP Protocol Suite 7
8 Figure 15.3 Sending and receiving buffers Buffer is a circular array Sender: White: Blue: data sent but not yet acknowledged Gray: data sent and acknowledged Receiver: White: Blue: received data Stream of bytes TCP/IP Protocol Suite 8
9 Figure 15.4 TCP segments TCP group a number of bytes together into a packet called a segment Segements are not necessarily all the same size Segment N H Segment 1 H TCP/IP Protocol Suite 9
10 TCP Services Process-to-Process Communication Stream-oriented Service UDP send messages with predefined boundaries TCP deliver and receive data as a stream of bytes Full-Duplex Service Data can flow in both direction at the same time Connection-Oriented Service Reliable Service Acknowledgement mechanism TCP/IP Protocol Suite 10
11 15-2 TCP FEATURES To provide the services mentioned in the previous section, TCP has several features that are briefly summarized in this section and discussed later in detail. TCP/IP Protocol Suite 11
12 TCP Numbering System Numbering System Byte number: between 0 and , the numbering may not start from 0 Sequence number for each segment is the number of the first byte Acknowledgement number defines the next byte that expected to receive The acknowledgement number is cumulative TCP/IP Protocol Suite 12
13 Example 15.1 Suppose a TCP connection is transferring a file of 5,000 bytes. The first byte is numbered 10,001. What are the sequence numbers for each segment if data are sent in five segments, each carrying 1,000 bytes? Solution The following shows the sequence number for each segment: TCP/IP Protocol Suite 13
14 Note The bytes of data being transferred in each connection are numbered by TCP. The numbering starts with an arbitrarily generated number. TCP/IP Protocol Suite 14
15 Note The value in the sequence number field of a segment defines the number assigned to the first data byte contained in that segment. TCP/IP Protocol Suite 15
16 Note The value of the acknowledgment field in a segment defines the number of the next byte a party expects to receive. The acknowledgment number is cumulative. TCP/IP Protocol Suite 16
17 15-3 SEGMENT Before discussing TCP in more detail, let us discuss the TCP packets themselves. A packet in TCP is called a segment. TCP/IP Protocol Suite 17
18 Figure 15.5 TCP segment format TCP/IP Protocol Suite 18
19 Figure 15.6 Control field TCP/IP Protocol Suite 19
20 Note The use of the checksum in TCP is mandatory. TCP/IP Protocol Suite 20
21 Figure 15.8 Encapsulation TCP header Application-layer data IP header Frame header Data-link layer payload TCP payload IP payload TCP/IP Protocol Suite 21
22 15-4 A TCP CONNECTION TCP is connection-oriented. It establishes a virtual path between the source and destination. All of the segments belonging to a message are then sent over this virtual path. You may wonder how TCP, which uses the services of IP, a connectionless protocol, can be connection-oriented. The point is that a TCP connection is virtual, not physical. TCP operates at a higher level. TCP uses the services of IP to deliver individual segments to the receiver, but it controls the connection itself. If a segment is lost or corrupted, it is retransmitted. TCP/IP Protocol Suite 22
23 Connection Establishment Three-way handshaking Connection Establishment Passive open: server tells its TCP that it is ready to accept a connection Active open: client issues a request Data Transfer Connection Termination TCP/IP Protocol Suite 23
24 Figure 15.9 Connection establishment using three-way handshake seq: 8000 U A P R S F SYN seq: 8000 ack: rwnd: U A P R S F ACK U A P R S F seq: ack: 8001 rwnd: 5000 SYN + ACK TCP/IP Protocol Suite 24
25 Note A SYN segment cannot carry data, but it consumes one sequence number. TCP/IP Protocol Suite 25
26 Note A SYN + ACK segment cannot carry data, but does consume one sequence number. TCP/IP Protocol Suite 26
27 Note An ACK segment, if carrying no data, consumes no sequence number. TCP/IP Protocol Suite 27
28 Figure Data Transfer Connection Termination TCP/IP Protocol Suite 28
29 Figure Connection termination using three-way handshake TCP/IP Protocol Suite 29
30 Note The FIN segment consumes one sequence number if it does not carry data. TCP/IP Protocol Suite 30
31 Note The FIN + ACK segment consumes one sequence number if it does not carry data. TCP/IP Protocol Suite 31
32 Figure Half-Close TCP/IP Protocol Suite 32
33 Connection Reset TCP may deny a connection request, may abort an existing Connection, may terminate an idle connection. All of these are done with the RST (reset) flag. TCP/IP Protocol Suite 33
34 15-6 WINDOWS IN TCP Before discussing data transfer in TCP and the issues such as flow, error, and congestion control, we describe the windows used in TCP. TCP uses two windows (send window and receive window) for each direction of data transfer, which means four windows for a bidirectional communication. To make the discussion simple, we make an assumption that communication is only unidirectional; the bidirectional communication can be inferred using two unidirectional communications with piggybacking. TCP/IP Protocol Suite 34
35 Figure Sliding window in circular format TCP/IP Protocol Suite 35
36 Figure Sliding window in linear format TCP/IP Protocol Suite 36
37 Topics Discussed in the Section Send Window Sending window size is dictated by the receiver and the congestion Three status Open, close, shrink Receive Window Two status: open, close It should never shrink TCP/IP Protocol Suite 37
38 Figure Send window in TCP TCP/IP Protocol Suite 38
39 Figure Receive window in TCP TCP/IP Protocol Suite 39
40 15-7 FLOW CONTROL As discussed before, flow control balances the rate a producer creates data with the rate a consumer can use the data. TCP separates flow control from error control. In this section we discuss flow control, ignoring error control. We temporarily assume that the logical channel between the sending and receiving TCP is error-free. Figure shows unidirectional data transfer between a sender and a receiver; bidirectional data transfer can be deduced from unidirectional one. TCP/IP Protocol Suite 40
41 Figure TCP/IP protocol suite Messages are pushed 1 5 Flow control feedback 3 Messages are pulled 2 Segements are pushed 4 Flow control feedback Opening and closing windows The receive window close when more bytes arrive from the sender; it opens when more bytes are pulled; it doesn t shrink The opening, closing, and shrinking of the send window is controlled by the receiver TCP/IP Protocol Suite 41
42 Figure An example of flow control TCP/IP Protocol Suite 42
43 Shrink of Windows The send window can shrink The receive window CANNOT shrink new ackno + new rwnd >= last ackno + last rwnd The receive window can temporarily shut down by sending a rwnd of 0. TCP/IP Protocol Suite 43
44 Figure Example 15.2 TCP/IP Protocol Suite 44
45 15-8 ERROR CONTROL TCP is a reliable transport layer protocol. This means that an application program that delivers a stream of data to TCP relies on TCP to deliver the entire stream to the application program on the other end in order, without error, and without any part lost or duplicated. Error control in TCP is achieved through the use of three tools: checksum, acknowledgment, and time-out. TCP/IP Protocol Suite 45
46 Error Control Tools Checksum: mandatory Acknowledgment: Cumulative Acknowledgement (ACK) Selective Acknowledgement (SACK) Report out of order, or duplicated data Retransmission: After Retransmission Time-Out (RTO) After three duplicate ACK segments --- fast retransmission TCP/IP Protocol Suite 46
47 Note ACK segments do not consume sequence numbers and are not acknowledged. TCP/IP Protocol Suite 47
48 Note Data may arrive out of order and be temporarily stored by the receiving TCP, but TCP guarantees that no out-of-order data are delivered to the process. The receiver TCP delivers only ordered data to the process. TCP/IP Protocol Suite 48
49 15-9 CONGESTION CONTROL Congestion may occur if the load on the network (the number of packages sent to the network) is greater than the capacity of the network (the number of packages a network can handle). TCP uses a congestion window (cwnd) and a congestion policy that avoid congestion and detect and alleviate congestion after it has occurred. TCP/IP Protocol Suite 49
50 Congestion Control in TCP Congestion Window: Actual window size = minimum(rwnd, cwnd) Congestion Policy Slow start: cwnd start with one maximum segment size (MSS), but grows exponentially, until it reaches a slow start threshold (ssthresh) Congestion avoidance: increase cwnd additively instead of exponentially until congestion is detected Congestion detection: congestion occurs when retransmission is needed RTO timer times out: Strong possibility of congestion ssthressh dropped to half: cwnd = 1; start the slow start phase again Three duplicate ACKs: Weak possibility of congestion ssthressh dropped to half; cwnd = ssthressh; start the congestion avoidance phase again TCP/IP Protocol Suite 50
51 Figure Slow start, exponential increase TCP/IP Protocol Suite 51
52 Note In the slow start algorithm, the size of the congestion window increases exponentially until it reaches a threshold. TCP/IP Protocol Suite 52
53 Figure Congestion avoidance, additive increase TCP/IP Protocol Suite 53
54 Note In the congestion avoidance algorithm the size of the congestion window increases additively until congestion is detected. TCP/IP Protocol Suite 54
55 Figure TCP Congestion policy summary TCP/IP Protocol Suite 55
56 Figure Congestion example TCP/IP Protocol Suite 56
57 15-10 TCP TIMERS To perform its operation smoothly, most TCP implementations use at least four timers as shown in Figure (slide 83). TCP/IP Protocol Suite 57
58 Figure TCP timers Persistence Timer: deal with zero-window-size segment Keepalive Timer: prevent a long idle connections TIME-WAIT Timer: used for connection termination TCP/IP Protocol Suite 58
59 Retransmission Timer Round-trip time (RTT) Measured RTT (RTT M ) Smoothed RTT (RTT S ) RTT Deviation (RTT D ) TCP/IP Protocol Suite 59
60 Figure No-operation option Smoother RTT RTT Deviation Retransmission Time-out (RTO) D α = 1/8 β = 1/4 TCP/IP Protocol Suite 60
61 Figure Example 15.3 TCP/IP Protocol Suite 61
62 Example 15.3 Let us give a hypothetical example. Figure shows part of a connection. The figure shows the connection establishment and part of the data transfer phases. 1. When the SYN segment is sent, there is no value for RTTM, RTTS, or RTTD. The value of RTO is set to 6.00 seconds. The following shows the value of these variable at this moment: 2. When the SYN+ACK segment arrives, RTTM is measured and is equal to 1.5 seconds. TCP/IP Protocol Suite 62
63 Example 15.3 Let us give a hypothetical example. Figure shows part of a connection. The figure shows the connection establishment and part of the data transfer phases. 1. When the SYN segment is sent, there is no value for RTTM, RTTS, or RTTD. The value of RTO is set to 6.00 seconds. The following shows the value of these variable at this moment: 2. When the SYN+ACK segment arrives, RTTM is measured and is equal to 1.5 seconds. TCP/IP Protocol Suite 63
64 Example 15.3 Continued 3. When the first data segment is sent, a new RTT measurement starts. No RTT measurement starts for the second data segment because a measurement is already in progress. The arrival of the last ACK segment is used to calculate the next value of RTTM. Although the last ACK segment acknowledges both data segments (cumulative), its arrival finalizes the value of RTTM for the first segment. The values of these variables are now as shown below. TCP/IP Protocol Suite 64
65 Karn s Algorithm A segment is not acknowledged --- Karn s Algorithm Do not update the value of RTTs until you send a segment and receive an acknowledgement without the need for retransmission Exponential Backoff The value of RTO is double for each retransmission TCP/IP Protocol Suite 65
66 Figure Example 15.4 TCP/IP Protocol Suite 66
67 15-11 OPTIONS The TCP header can have up to 40 bytes of optional information. Options convey additional information to the destination or align other options. We can define two categories of options: 1-byte options and multiplebyte options. The first category contains two types of options: end of option list and no operation. The second category, in most implementations, contains five types of options: maximum segment size, window scale factor, timestamp, SACK-permitted, and SACK (see Figure 15.41). TCP/IP Protocol Suite 67
68 Figure Options TCP/IP Protocol Suite 68
69 Figure End-of-option option TCP/IP Protocol Suite 69
70 Note EOP can be used only once. TCP/IP Protocol Suite 70
71 Figure No-operation option TCP/IP Protocol Suite 71
72 Note NOP can be used more than once. TCP/IP Protocol Suite 72
73 Figure Maximum-segment-size option MSS option defines the size of the biggest unit of data that can be received by the destination of the TCP segment The default value is 536 bytes TCP/IP Protocol Suite 73
74 Note The value of MSS is determined during connection establishment and does not change during the connection. TCP/IP Protocol Suite 74
75 Figure Window-scale-factor option New window size = window size defined in the header * 2 window scale factor TCP/IP Protocol Suite 75
76 Note The value of the window scale factor can be determined only during connection establishment; it does not change during the connection. TCP/IP Protocol Suite 76
77 Figure Timestamp option TCP/IP Protocol Suite 77
78 Note One application of the timestamp option is the calculation of round-trip time (RTT). TCP/IP Protocol Suite 78
79 Figure Example 15.5 TCP/IP Protocol Suite 79
80 Figure SACK TCP/IP Protocol Suite 80
81 Example 15.6 Let us see how the SACK option is used to list out-of-order blocks. In Figure an end has received five segments of data. TCP/IP Protocol Suite 81
82 Example 15.7 Figure shows how a duplicate segment can be detected with a combination of ACK and SACK. In this case, we have some out-of-order segments (in one block) and one duplicate segment. To show both out-of-order and duplicate data, SACK uses the first block, in this case, to show the duplicate data and other blocks to show out-of-order data. Note that only the first block can be used for duplicate data. The natural question is how the sender, when it receives these ACK and SACK values, knows that the first block is for duplicate data (compare this example with the previous example). The answer is that the bytes in the first block are already acknowledged in the ACK field; therefore, this block must be a duplicate. TCP/IP Protocol Suite 82
83 Figure Example 15.7 TCP/IP Protocol Suite 83
84 Example 15.8 Figure shows what happens if one of the segments in the out-of-order section is also duplicated. In this example, one of the segments (4001:5000) is duplicated. The SACK option announces this duplicate data first and then the out-of-order block. This time, however, the duplicated block is not yet acknowledged by ACK, but because it is part of the out-of-order block (4001:5000 is part of 4001:6000), it is understood by the sender that it defines the duplicate data. TCP/IP Protocol Suite 84
85 Figure Example 15.8 TCP/IP Protocol Suite 85
86 Summaries: To introduce TCP as a protocol that provides reliable stream delivery service. To define TCP features and compare them with UDP features. To define the format of a TCP segment and its fields. To show how TCP provides a connection-oriented service, and show the segments exchanged during connection establishment and connection termination phases. To discuss the state transition diagram for TCP and discuss some scenarios. To introduce windows in TCP that are used for flow and error control. TCP/IP Protocol Suite 86
87 Summaries (continued): To discuss how TCP implements flow control in which the receive window controls the size of the send window. To discuss error control and FSMs used by TCP during the data transmission phase. To discuss how TCP controls the congestion in the network using different strategies. To list and explain the purpose of each timer in TCP. To discuss options in TCP and show how TCP can provide selective acknowledgment using the SACK option. TCP/IP Protocol Suite 87
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
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
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
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
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
TCP 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
TCP 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
TCP 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
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
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
This sequence diagram was generated with EventStudio System Designer (http://www.eventhelix.com/eventstudio).
Client App Network Server App 25-May-13 15:32 (Page 1) This sequence diagram was generated with EventStudio System Designer (http://www.eventhelix.com/eventstudio). TCP is an end to end protocol which
[Prof. Rupesh G Vaishnav] Page 1
![[Prof. Rupesh G Vaishnav] Page 1](/thumbs/26/7709048.jpg "[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
Access Control: Firewalls (1)
Access Control: Firewalls (1) World is divided in good and bad guys ---> access control (security checks) at a single point of entry/exit: in medieval castles: drawbridge in corporate buildings: security/reception
Improving 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.
CSE 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
A 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
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
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 [email protected] Cours de C. Pham,
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
TCP 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/
Simulation-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
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
TCP/IP Networking for Wireless Systems. Integrated Communication Systems Group Ilmenau University of Technology
TCP/IP Networking for Wireless Systems Integrated Communication Systems Group Ilmenau University of Technology Content Internet Protocol Suite Link Layer: Ethernet, PPP, ARP, MAC Addressing Network Layer:
Prefix 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?
Overview. Securing TCP/IP. Introduction to TCP/IP (cont d) Introduction to TCP/IP
Overview Securing TCP/IP Chapter 6 TCP/IP Open Systems Interconnection Model Anatomy of a Packet Internet Protocol Security (IPSec) Web Security (HTTP over TLS, Secure-HTTP) Lecturer: Pei-yih Ting 1 2
CPS221 Lecture: Layered Network Architecture
CPS221 Lecture: Layered Network Architecture Objectives last revised 9/10/12 1. To discuss the OSI layered architecture model 2. To discuss the specific implementation of this model in TCP/IP Materials:
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
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)
Lecture 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
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)
TCP Performance Management for Dummies
TCP Performance Management for Dummies Nalini Elkins Inside Products, Inc. Monday, August 8, 2011 Session Number 9285 Our SHARE Sessions Orlando 9285: TCP/IP Performance Management for Dummies Monday,
Visualizations and Correlations in Troubleshooting
Visualizations and Correlations in Troubleshooting Kevin Burns Comcast [email protected] 1 Comcast Technology Groups Cable CMTS, Modem, Edge Services Backbone Transport, Routing Converged Regional
First 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
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
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
TCP/IP Fundamentals. OSI Seven Layer Model & Seminar Outline
OSI Seven Layer Model & Seminar Outline TCP/IP Fundamentals This seminar will present TCP/IP communications starting from Layer 2 up to Layer 4 (TCP/IP applications cover Layers 5-7) IP Addresses Data
How do I get to www.randomsite.com?
Networking Primer* *caveat: this is just a brief and incomplete introduction to networking to help students without a networking background learn Network Security. How do I get to www.randomsite.com? Local
Mobile 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
Data 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.
LESSON 3.6. 98-366 Networking Fundamentals. Understand TCP/IP
Understand TCP/IP Lesson Overview In this lesson, you will learn about: TCP/IP Tracert Telnet Netstat Reserved addresses Local loopback IP Ping Pathping Ipconfig Protocols Anticipatory Set Experiment with
Transport layer issues in ad hoc wireless networks Dmitrij Lagutin, [email protected]
Transport layer issues in ad hoc wireless networks Dmitrij Lagutin, [email protected] 1. Introduction Ad hoc wireless networks pose a big challenge for transport layer protocol and transport layer protocols
La couche transport dans l'internet (la suite TCP/IP)
La couche transport dans l'internet (la suite TCP/IP) C. Pham RESO-LIP/INRIA Université Lyon 1 http://www.ens-lyon.fr/~cpham Basé sur les transparent de Shivkumar Kalyanaraman La couche transport dans
Lecture 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
CSE331: 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
Transport layer protocols for ad hoc networks
Transport layer protocols for ad hoc networks Lecturer: Dmitri A. Moltchanov E-mail: [email protected] http://www.cs.tut.fi/kurssit/tlt-2616/ Which transport layer protocol? Classification of transport
Computer Networks. Data Link Layer
Computer Networks The Data Link Layer 1 Data Link Layer Application Transport Network DLL PHY 2 What does it do? What functions it performs? Typically: Handling transmission errors, a.k.a., error control.
Congestions 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
Data Link Layer(1) Principal service: Transferring data from the network layer of the source machine to the one of the destination machine
Data Link Layer(1) Principal service: Transferring data from the network layer of the source machine to the one of the destination machine Virtual communication versus actual communication: Specific functions
2 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
TCP 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
Stop And Wait. ACK received; transmit frame 2 CS 455 3
Data Link Layer, Part 5 Sliding Window Protocols These slides are created by Dr. Yih Huang of George Mason University. Students registered in Dr. Huang's courses at GMU can make a single machine-readable
IP address format: Dotted decimal notation: 10000000 00001011 00000011 00011111 128.11.3.31
IP address format: 7 24 Class A 0 Network ID Host ID 14 16 Class B 1 0 Network ID Host ID 21 8 Class C 1 1 0 Network ID Host ID 28 Class D 1 1 1 0 Multicast Address Dotted decimal notation: 10000000 00001011
Chapter 3. TCP/IP Networks. 3.1 Internet Protocol version 4 (IPv4)
Chapter 3 TCP/IP Networks 3.1 Internet Protocol version 4 (IPv4) Internet Protocol version 4 is the fourth iteration of the Internet Protocol (IP) and it is the first version of the protocol to be widely
TCP 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
Networking Test 4 Study Guide
Networking Test 4 Study Guide True/False Indicate whether the statement is true or false. 1. IPX/SPX is considered the protocol suite of the Internet, and it is the most widely used protocol suite in LANs.
TCP 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
Final 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 -
SELECTIVE-TCP FOR WIRED/WIRELESS NETWORKS
SELECTIVE-TCP FOR WIRED/WIRELESS NETWORKS by Rajashree Paul Bachelor of Technology, University of Kalyani, 2002 PROJECT SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF
Parallel 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
Recent advances in transport protocols
Recent advances in transport protocols April 12, 2013 Abstract Transport protocols play a critical role in today s Internet. This chapter first looks at the evolution of the Internet s Transport Layer
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)
Midterm 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
Final exam review, Fall 2005 FSU (CIS-5357) Network Security
Final exam review, Fall 2005 FSU (CIS-5357) Network Security Instructor: Breno de Medeiros 1. What is an insertion attack against a NIDS? Answer: An insertion attack against a network intrusion detection
Computer 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) ------------------------------------------------------------------------------
Per-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
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
High 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,
TRANSPORT LAYER AND SECURITY PROTOCOLS FOR AD HOC WIRELESS NETWORKS
Chapter 9 TRANSPORT LAYER AND SECURITY PROTOCOLS FOR AD HOC WIRELESS NETWORKS 9.1 INTRODUCTION The objectives of a transport layer protocol include the setting up of an end-to-end connection, end-to-end
Solution of Exercise Sheet 5
Foundations of Cybersecurity (Winter 15/16) Prof. Dr. Michael Backes CISPA / Saarland University saarland university computer science Protocols = {????} Client Server IP Address =???? IP Address =????
Transport and Network Layer
Transport and Network Layer 1 Introduction Responsible for moving messages from end-to-end in a network Closely tied together TCP/IP: most commonly used protocol o Used in Internet o Compatible with a
(Refer Slide Time: 02:17)
Internet Technology Prof. Indranil Sengupta Department of Computer Science and Engineering Indian Institute of Technology, Kharagpur Lecture No #06 IP Subnetting and Addressing (Not audible: (00:46)) Now,
A 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
A 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
Internet Packets. Forwarding Datagrams
Internet Packets Packets at the network layer level are called datagrams They are encapsulated in frames for delivery across physical networks Frames are packets at the data link layer Datagrams are formed
Chapter 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;
Pig Laboratory. Additional documentation for the laboratory. Exercises and Rules. Tstat Data
Pig Laboratory This laboratory is dedicated to Hadoop Pig and consists of a series of exercises: some of them somewhat mimic those in the MapReduce laboratory, others are inspired by "real-world" problems.
Networks: IP and TCP. Internet Protocol
Networks: IP and TCP 11/1/2010 Networks: IP and TCP 1 Internet Protocol Connectionless Each packet is transported independently from other packets Unreliable Delivery on a best effort basis No acknowledgments
Chapter 11. User Datagram Protocol (UDP)
Chapter 11 User Datagram Protocol (UDP) The McGraw-Hill Companies, Inc., 2000 1 CONTENTS PROCESS-TO-PROCESS COMMUNICATION USER DATAGRAM CHECKSUM UDP OPERATION USE OF UDP UDP PACKAGE The McGraw-Hill Companies,
Command Manual - Network Protocol Quidway S3000 Series Ethernet Switches. Table of Contents
Table of Contents Table of Contents Chapter 1 ARP Configuration Commands... 1-1 1.1 ARP Configuration Commands... 1-1 1.1.1 arp static... 1-1 1.1.2 arp timer aging... 1-2 1.1.3 debugging arp packet...
Optimization 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
Effect of Packet-Size over Network Performance
International Journal of Electronics and Computer Science Engineering 762 Available Online at www.ijecse.org ISSN: 2277-1956 Effect of Packet-Size over Network Performance Abhi U. Shah 1, Daivik H. Bhatt
First 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
Configuring TCP Intercept (Preventing Denial-of-Service Attacks)
Configuring TCP Intercept (Preventing Denial-of-Service Attacks) This chapter describes how to configure your router to protect TCP servers from TCP SYN-flooding attacks, a type of denial-of-service attack.
Mobile Computing/ Mobile Networks
Mobile Computing/ Mobile Networks TCP in Mobile Networks Prof. Chansu Yu Contents Physical layer issues Communication frequency Signal propagation Modulation and Demodulation Channel access issues Multiple
COMP 361 Computer Communications Networks. Fall Semester 2003. Midterm Examination
COMP 361 Computer Communications Networks Fall Semester 2003 Midterm Examination Date: October 23, 2003, Time 18:30pm --19:50pm Name: Student ID: Email: Instructions: 1. This is a closed book exam 2. This
Low-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
Troubleshooting Tips and Tricks
Troubleshooting Tips and Tricks for TCP/IP Networks June 16, 2011 Laura Chappell Founder Chappell University/Wireshark University [email protected] SHARKFEST 11 Stanford University June 13 16, 2011 The
CS335 Sample Questions for Exam #2
CS335 Sample Questions for Exam #2.) Compare connection-oriented with connectionless protocols. What type of protocol is IP? How about TCP and UDP? Connection-oriented protocols Require a setup time to
Introduction to IP networking
DD2395 p2 2011 Introduction to IP networking Olof Hagsand KTH CSC 1 Example: Packet transfer www.server.org An end host requests a web-page from a server via a local-area network The aim of this lecture
CSMA/CA. Information Networks p. 1
Information Networks p. 1 CSMA/CA IEEE 802.11 standard for WLAN defines a distributed coordination function (DCF) for sharing access to the medium based on the CSMA/CA protocol Collision detection is not
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
The present and the future of TCP/IP
The present and the future of TCP/IP David Espina Project in Electronics [email protected] Dariusz Baha Computer science [email protected] ABSTRACT The Transport Control Protocol (TCP) and
IP - The Internet Protocol
Orientation IP - The Internet Protocol IP (Internet Protocol) is a Network Layer Protocol. IP s current version is Version 4 (IPv4). It is specified in RFC 891. TCP UDP Transport Layer ICMP IP IGMP Network
Application 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
An 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,