TCP Flow Control and Connection Management Quiz
75 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of flow control in TCP?

  • To ensure data is transmitted without any loss.
  • To establish a secure connection between sender and receiver.
  • To manage the rate at which the sender transmits data. (correct)
  • To control the amount of data transmitted by the receiver.

    • How is the free buffer space communicated from the receiver to the sender in TCP?

  • By including the rwnd value in the TCP header. (correct)
  • With the acknowledgment of received data packets.
  • By sending control messages in UDP segments.
  • Through the SYN flag during the connection establishment.

    • Which of the following statements accurately describes the connection management process in TCP?

  • It initializes the connection without checking buffer sizes.
  • It uses a three-way handshake to establish a connection.
  • It does not involve any parameters to agree upon.
  • It requires both sender and receiver to confirm readiness to connect. (correct)

    • What is the role of the RcvBuffer in TCP communication?

    <p>To hold incoming data until it can be processed by the application.</p> Signup and view all the answers

    In a 2-way TCP handshake, what is essential for both sender and receiver?

    <p>They need to agree on the sequence numbers to use.</p> Signup and view all the answers

    What is the typical default size of the RcvBuffer in TCP?

    <p>4096 bytes</p> Signup and view all the answers

    Which of the following best describes demultiplexing in the context of TCP?

    <p>Receiving data and separating it for different applications.</p> Signup and view all the answers

    What is the first step in the TCP 3-way handshake process?

    <p>Client sends a SYN message.</p> Signup and view all the answers

    Which state indicates that both the client and server are ready to communicate after the handshake?

    <p>ESTAB</p> Signup and view all the answers

    During the closing process of a TCP connection, what does the FIN bit indicate?

    <p>The sender wants to terminate the connection.</p> Signup and view all the answers

    Which state is the client in after it sends a FIN message but is still waiting for the server to close its side?

    <p>FIN_WAIT_1</p> Signup and view all the answers

    What does the TCP segment contain when a client sends an acknowledgment for a received SYN-ACK?

    <p>ACKbit=1, ACKnum=y+1</p> Signup and view all the answers

    Which of the following is NOT a principle of TCP congestion control?

    <p>Flow control</p> Signup and view all the answers

    In socket programming, what action does the server take to accept incoming client connections?

    <p>create a new socket</p> Signup and view all the answers

    What is the purpose of demultiplexing in transport-layer protocols?

    <p>Direct incoming segments to the correct application process.</p> Signup and view all the answers

    Which TCP state follows the FIN_WAIT_2 state when the client has received a FIN message from the server?

    <p>LAST_ACK</p> Signup and view all the answers

    What identifies a TCP socket in connection-oriented communication?

    <p>Source IP address, source port number, destination IP address, and destination port number</p> Signup and view all the answers

    Which of the following statements about demultiplexing is accurate?

    <p>Demultiplexing relies on all four values of the 4-tuple to route segments correctly.</p> Signup and view all the answers

    In a threaded server, how does each client interact with the server?

    <p>Each client is assigned a different socket identified by its own 4-tuple.</p> Signup and view all the answers

    Which of the following is a characteristic of the User Datagram Protocol (UDP)?

    <p>It is suitable for applications that are loss-tolerant.</p> Signup and view all the answers

    What is the primary purpose of connection management in TCP?

    <p>To establish, maintain, and terminate connections reliably.</p> Signup and view all the answers

    What happens to UDP segments during transmission that distinguishes it from TCP?

    <p>UDP segments may be delivered out-of-order and may be lost.</p> Signup and view all the answers

    Which of the following best describes the reliable data transfer features of TCP?

    <p>It incorporates mechanisms for error detection and flow control.</p> Signup and view all the answers

    Which of the following applications is most suited for UDP?

    <p>Streaming multimedia applications that can tolerate some data loss</p> Signup and view all the answers

    In TCP, which component is crucial for flow control?

    <p>Sliding Window Protocol</p> Signup and view all the answers

    In Go-back-N, the sender retransmits all unacknowledged packets when a timeout occurs.

    <p>True</p> Signup and view all the answers

    Selective Repeat allows the sender to receive cumulative acknowledgments for lost packets.

    <p>False</p> Signup and view all the answers

    The receiver in a Go-back-N protocol buffers out-of-order packets.

    <p>False</p> Signup and view all the answers

    In Selective Repeat, the sender maintains a separate timer for each unacknowledged packet.

    <p>True</p> Signup and view all the answers

    In Go-back-N, receiving duplicate acknowledgments indicates that there is a gap in the sequence of packets.

    <p>True</p> Signup and view all the answers

    The network layer is responsible for reliable, in-order delivery of data between processes.

    <p>False</p> Signup and view all the answers

    UDP is a connection-oriented protocol that guarantees delivery and order of messages.

    <p>False</p> Signup and view all the answers

    Demultiplexing utilizes header information to direct received segments to the correct socket.

    <p>True</p> Signup and view all the answers

    TCP includes features such as flow control and congestion control to manage data transfer.

    <p>True</p> Signup and view all the answers

    Both TCP and UDP provide delay and bandwidth guarantees.

    <p>False</p> Signup and view all the answers

    TCP is a connectionless transport protocol that does not require handshaking.

    <p>False</p> Signup and view all the answers

    The maximum segment size (MSS) is a feature of TCP that defines the largest amount of data that can be sent in a single segment.

    <p>True</p> Signup and view all the answers

    TCP guarantees the delivery of data in the order it was sent, ensuring a reliable data stream.

    <p>True</p> Signup and view all the answers

    In the TCP segment structure, the RST, SYN, and FIN flags are used for data flow control during transmission.

    <p>False</p> Signup and view all the answers

    Flow control in TCP prevents the sender from overwhelming the receiver with too much data.

    <p>True</p> Signup and view all the answers

    TCP segments have message boundaries that are preserved during transmission.

    <p>False</p> Signup and view all the answers

    Pipelining in TCP allows multiple segments to be sent before receiving an acknowledgment for the first one.

    <p>True</p> Signup and view all the answers

    In selective repeat ARQ, the receiver window size can affect the delivery of packets.

    <p>True</p> Signup and view all the answers

    A window size of 3 allows three packets to be in transit before an acknowledgment is required.

    <p>True</p> Signup and view all the answers

    In scenario (b), duplicate data is always rejected by the receiver.

    <p>False</p> Signup and view all the answers

    The sequence number size is irrelevant to avoid problems in selective repeat protocols.

    <p>False</p> Signup and view all the answers

    If a sender retransmits pkt0 after a timeout, the receiver will always accept it with the same sequence number.

    <p>True</p> Signup and view all the answers

    After receipt of a packet, the receiver cannot discern the sender's behavior in selective repeat protocols.

    <p>True</p> Signup and view all the answers

    In the selective repeat mechanism, the relationship between sequence number size and window size is critical to avoid issues.

    <p>True</p> Signup and view all the answers

    In scenario (a), the sender and receiver behave differently when handling the same packet.

    <p>False</p> Signup and view all the answers

    A DatagramSocket is used to direct a UDP segment to a socket with that port #, which is identified by the destination ______.

    <p>port</p> Signup and view all the answers

    In the example, the source IP addresses and/or source ______ numbers will be directed to the same socket at the destination.

    <p>port</p> Signup and view all the answers

    DatagramSocket mySocket1 was created with a source port of 5775, while mySocket2 was created with a source port of ______.

    <p>9157</p> Signup and view all the answers

    When working with UDP, the destination port is important for ensuring that the ______ segment reaches the correct application.

    <p>UDP</p> Signup and view all the answers

    The process of determining which socket to send UDP segments to is referred to as ______ demultiplexing.

    <p>connectionless</p> Signup and view all the answers

    Transport protocols provide logical communication between application processes running on different ______.

    <p>hosts</p> Signup and view all the answers

    In connection-oriented transport, the protocol used is ______.

    <p>TCP</p> Signup and view all the answers

    The transport layer is responsible for breaking application messages into ______.

    <p>segments</p> Signup and view all the answers

    Demultiplexing utilizes header information to direct received segments to the correct ______.

    <p>socket</p> Signup and view all the answers

    Flow control in TCP is important to prevent the sender from overwhelming the ______.

    <p>receiver</p> Signup and view all the answers

    In rdt3.0, the sender must specify the ______ of the packet being acknowledged.

    <p>sequence number</p> Signup and view all the answers

    In the event of a timeout, the sender will ______ the packet that was not acknowledged.

    <p>resend</p> Signup and view all the answers

    The process of maintaining a countdown timer is critical in ______ to track unacknowledged packets.

    <p>rdt3.0</p> Signup and view all the answers

    When an acknowledgment for a packet is lost, the sender may experience a ______.

    <p>timeout</p> Signup and view all the answers

    After receiving a duplicate packet, the receiver in rdt3.0 can ______ it to avoid processing it again.

    <p>detect</p> Signup and view all the answers

    In rdt3.0, the sender starts a timer when it ______ a packet.

    <p>sends</p> Signup and view all the answers

    The sender's state in rdt3.0 can change based on whether the received packet is ______ or not.

    <p>corrupt</p> Signup and view all the answers

    In rdt2.0, the sender relies on control messages such as ______ to confirm successful packet reception.

    <p>ACK</p> Signup and view all the answers

    A negative acknowledgment, or ______, indicates that the packet had errors.

    <p>NAK</p> Signup and view all the answers

    In rdt2.0, ______ is used to detect errors in the transmitted packets.

    <p>checksum</p> Signup and view all the answers

    Upon receiving a ______, the sender retransmits the packet.

    <p>NAK</p> Signup and view all the answers

    The process of delivering the data from the internal packet structure is known as ______.

    <p>extract</p> Signup and view all the answers

    In the rdt2.0 protocol, the sender must wait for an ______ or NAK response from the receiver.

    <p>ACK</p> Signup and view all the answers

    When there are no errors, the receiver sends an ______ back to the sender.

    <p>ACK</p> Signup and view all the answers

    Utilizing effective mechanisms for error detection and feedback is an improvement in ______ compared to earlier protocols.

    <p>rdt2.0</p> Signup and view all the answers

    Study Notes

    Computer Networking Study Notes

    • A note on the use of these PPT slides:
      • The slides are freely available for faculty, students, and readers.
      • They are in PowerPoint format, allowing for animations and modifications.
      • Users can add, modify, and delete slides and content.
      • These slides represent substantial work on the authors' part, and they only request that users credit the source and acknowledge copyright if posting the slides on a website.

    Chapter 3: 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
      • segment structure
      • reliable data transfer
      • flow control
      • connection management
    • 3.6 principles of congestion control
    • 3.7 TCP congestion control

    Transport Services and Protocols

    • Provide logical communication between application processes on different hosts.
    • Transport protocols run in end systems.
    • Send side: breaks application messages into segments, delivers them to the network layer.
    • Receive side: reassembles segments into messages, delivers them to the application layer.
    • Multiple transport protocols are available on the Internet (e.g., TCP and UDP).

    Transport Layer vs. Network Layer

    • Network layer: logical communication between hosts.
    • Transport layer: logical communication between processes that relies on and enhances the network layer.

    Internet Transport-Layer Protocols

    • Reliable, in-order delivery (TCP)
      • congestion control
      • flow control
      • connection setup
    • Unreliable, unordered delivery (UDP)
      • no-frills extension of "Best Effort" IP services
      • delay and bandwidth guarantees not available

    Multiplexing/Demultiplexing

    • Multiplexing at sender: handles data from multiple sockets, adds transport header.
    • Demultiplexing at receiver: uses header information to deliver received segments to the correct socket.

    How Demultiplexing Works

    • Host receives IP datagrams.
    • Each datagram has source and destination IP addresses.
    • Each datagram carries one transport-layer segment.
    • Each segment has source and destination port numbers.
    • Host uses IP addresses and port numbers to direct segment to appropriate socket.

    Connectionless Demultiplexing

    • When host receives UDP segment:
      • Checks destination port number in segment.
      • Directs UDP segment to socket with that port number.

    Connectionless Demultiplexing: Example

    • Specific socket creation examples using DatagramSocket
    • Illustrates how destination ports direct incoming UDP segments.

    Connection-Oriented Demultiplexing

    • TCP socket identified by 4-tuple.
      • source IP address
      • source port number
      • destination IP address
      • destination port number
    • Receiver uses all four values to direct segment to appropriate socket.

    Connection-Oriented Demultiplexing: Example

    • Illustrates how the 4-tuple identifies the specific TCP connection.

    UDP: User Datagram Protocol

    • "No frills," "bare bones" Internet transport protocol.
    • "Best effort" service; UDP segments may be lost or delivered out-of-order.
    • UDP use cases: streaming multimedia, DNS
    • Reliable transfer can be added at the application layer.

    UDP Segment Header

    • Header contains source and destination port numbers, length, and checksum fields.
    • Lightweight design allows fast data transmission.

    UDP Checksum

    • Checks for errors (e.g., bit flips) during transmission.
    • Sender calculates checksum of segment contents (one's complement sum).
    • Receiver calculates checksum of received segment.
    • If calculated checksum matches: no detected errors.

    Internet Checksum: Example

    • Shows example of adding two 16-bit integers to illustrate the checksum calculation.

    Chapter 4: Network Layer

    • 4.1 introduction
    • 4.2 virtual circuit and datagram networks
    • 4.3 what's inside a router
    • 4.4 IP: Internet Protocol
      • datagram format
      • IPv4 addressing
      • ICMP
      • IPv6
    • 4.5 routing algorithms
      • link state
      • distance vector
      • hierarchical routing
    • 4.6 routing in the Internet
      • RIP
      • OSPF
      • BGP
    • 4.7 broadcast and multicast routing

    Network Layer Functions

    • Forwarding: Moves packets from a router's input to appropriate output.
    • Routing: Determines the route taken by packets from source to destination, including routing algorithms.

    Interplay between Routing and Forwarding

    • Routing algorithm determines end-to-end path through a network.
    • Forwarding table determines local forwarding at each router.

    Connection Setup

    • 3rd important function in some network architectures.
    • Establishes virtual connections before datagrams flow.

    Network Service Model

    • Datagrams from sender to receiver
    • Example services for individual datagrams (e.g., guaranteed delivery with less than 40 msec delay)
    • Example services for a flow of datagrams (e.g., in-order delivery, guaranteed minimum bandwidth)

    Network Layer Service Models

    • Summarizes various network architectures and their associated service models, ensuring bandwidth, loss, order and timing guarantees in different contexts
    • Table summarizing network layer service types.

    Virtual Circuits

    • Source-to-destination path behaves like a telephone circuit,
    • Performance-wise and network actions are along the source-to-destination path.
    • Each packet carries a VC identifier, not a destination host address.
    • Each router maintains state for each passing connection.
    • Link, router resources (bandwidth, buffers) may be allocated to virtual circuits, resulting in predictable service.

    VC Implementation

    • A VC consists of:
      • path from source to destination
      • VC numbers for each link along the path
      • Entries in forwarding tables in routers along the path.
    • A packet belonging to a VC carries the VC number instead of the destination address.

    VC Forwarding Table

    • A forwarding table in a router provides mappings between incoming and outgoing VC numbers for each interface.

    Virtual Circuits: Signaling Protocols

    • Used to set up, maintain, and tear down virtual circuits.
    • Not used in today's Internet architectures.

    Datagram Networks

    • No call setup at the network layer.
    • Routers do not maintain state about end-to-end connections.
    • Packets are forwarded using the destination host address.

    Datagram Forwarding Table

    • Shows how destination addresses are listed in aggregate table blocks.

    Longest Prefix Matching

    • Used to select the most specific route from a set of possible routes in a forwarding table.

    Datagram or VC Network: Why?

    • Comparison between the two network models (datagram vs virtual circuit) and their suitable use cases,
    • advantages and disadvantages for their use in internet and related technologies

    Chapter 4 Outline (recap)

    Router Architecture Overview

    • Two Key Router Functions:
    • Run routing algorithms (RIP, OSPF, BGP).
    • Forwarding datagrams from incoming to outgoing links.
    • Routing Processor manages the control plane,
    • Switching Fabric handles the forwarding plane.

    Input Port Functions

    • Line Termination, Link Layer Protocol (receive), Lookup/Forwarding, Queuing, Decentralized Switching

    Switching Fabrics

    • Three types of fabrics:
      1. Memory
      2. Bus
      3. Switching Interconnection Network

    Switching via Memory

    • Describes datagram copying to system memory, limited by memory bandwidth.

    Switching via a Bus

    • Describes packet transfer over a shared bus, limited by bus contention.
    • Shows how switching speed is related to bus bandwidth.

    Switching via Interconnection Network

    • Describes how datagrams are fragmented and switched through specialized interconnection networks,
    • such as banyan networks and crossbars, often in high-speed networks such as multiprocessors.
    • Shows Cisco 12000 switch switches 60 Gbps thru interconnection network.

    Output Ports

    • Buffering required, frame rate into switch exceeds outgoing line speed
    • Scheduling datagrams to appropriate outgoing lines.

    Output Port Queuing

    • Describes how queuing leads to packet delays and losses when arrival rate exceeds output line speed.

    How Much Buffering?

    • Suggests that average buffering should equal RTT × link capacity.

    Input Port Queuing

    Describes how input port queuing can occur if the switching fabric is slower than combined input ports.

    Dijkstra's Algorithm

    • Algorithm to find least-cost path between all nodes in a network graph.
    • Detailed description of the algorithm steps and complexity.

    Dijkstra's Algorithm: Example

    • Practical examples of Dijkstra's algorithm in action.

    Dijkstra's Algorithm, Discussion

    • Elaborates on algorithm complexity, efficiency, and potential oscillations with dynamic link costs.

    Distance Vector Algorithm

    • Explanation of Bellman-Ford equation, used to calculate least cost paths.
    • Description of node X, which maintains a distance vector.
    • Key idea and convergence of estimates under optimal conditions.
    • Overview of the changes in local link costs triggering recalculations and updates in DV routing.
    • Handling neighbor notifications of these changes.
    • Explores "bad news travels slow" scenarios.
    • Explains "count-to-infinity" problem.

    Comparison of LS and DV Algorithms

    • Compares link state and distance vector algorithms on message complexity, robustness, and speed of convergence.

    Hierarchical Routing

    • Rationale for hierarchical routing, aggregating routers into AS regions.
    • Administrative responsibility and scale considerations for routing table exchange.

    Interconnected ASes

    • How intra-AS and inter-AS routing algorithms cooperate to manage an internet consisting of multiple ASes.

    Inter-AS Tasks

    • Overview of Inter-AS tasks in routing administration of individual ASes, learning about destinations reachable via other ASs and propagating reachability information throughout the entire AS.

    Example: Setting Forwarding Table in Router Id

    Example using a case study to configure a forwarding table in a router based on what was learned from a protocol about subnet reachability.

    Example: Choosing Among Multiple ASes

    • How a router makes decisions among various inter-AS routing paths based on criteria like shortest AS path.

    Hot Potato Routing

    • Describes the hot potato routing mechanism used to select the nearest gateway when choosing among multiple gateways towards a destination.

    How Does Entry Get in Forwarding Table?

    • High-level overview of the steps involved in adding a routing entry for a prefix in a router's forwarding table.

    BGP Routing Policy

    • Overview and examples of how administrative policies influence which routes routers select.

    BGP Route Selection

    • How a router selects the best available route to a specific destination AS based on various attributes.

    BGP Messages

    • Information on different types of BGP messages exchanged between BGP routers and how they are managed.

    TCP Reliable Data Transfer

    • Overview of TCP's reliable data transfer mechanism.

    TCP Sender Events

    • Explanation of the different events that could lead to triggering TCP retransmission and what the router would do.

    TCP Sender (Simplified)

    • A simplified overview of a TCP sender, focusing on the key elements for initiating and managing transmission.

    TCP: Retransmission Scenarios

    • Illustrations of how TCP handles retransmissions in different scenarios, like lost ACKs or premature timeouts.

    TCP ACK Generation

    • Events at the receiver side related to generating TCP ACKs and how they are handled.

    TCP Fast Retransmit

    • How TCP detects and reacts to segment losses without waiting for a time-out period.

    TCP Flow Control

    • Explaining how receiver controls sender to prevent buffer overflow at the receiving side.

    TCP Flow Control (Details)

    • Description of how the receiver advertises the free buffer space using the rwnd value included in the TCP header, preventing the sender from transmitting more packets than the receiver can handle.

    TCP Congestion Control (Details)

    • Explanation of the sender's sequence number space (cwnd), and the dynamic nature of cwnd as a function of perceived network congestion.
    • How TCP dynamically adjusts its sending rate based on congestion.

    TCP Slow Start

    • Describes how the TCP sender's transmission rate increases exponentially at the beginning of a connection, but eventually settles to a congestion-conscious rate.

    TCP: Detecting, Reacting to Loss

    • Describes how TCP detects segment transmission loss ( via timeout or three duplicated ACKs) and modifies sending behavior accordingly.

    TCP: Switching from Slow Start to CA

    • Describes the threshold transition from "slow start" to congestion avoidance in TCP, as the sender's congestion window grows toward to its threshold.

    Summary: TCP Congestion Control

    • A summary diagram showing the states/actions of congestion control mechanisms in TCP, summarizing the transitions between different phases.

    TCP Throughput

    • Discussion of how TCP throughput relates to window size and RTT, especially considering slow start,
    • giving the theoretical optimal throughput.

    TCP Futures (TCP over long, fat pipes)

    • Discussion of how TCP needs adaptation for high-bandwidth, low-loss networks.

    TCP Fairness

    • Explains how TCP protocols achieve fair resource sharing concerning different network connections.
    • Describes competing mechanisms between different TCP connections for bandwidth sharing in network congestion scenarios, giving an example.

    Fairness (More: TCP vs UDP)

    • Comparison of TCP and UDP in terms of their capabilities for fairness and suitability in different network scenarios
    • Discusses why multimedia and other applications might prefer UDP to TCP

    Chapter 5 Summary

    This section offers a concise summary of the key topics covered in Chapter 5, the Link Layer.

    Chapter 5: Let's Take a Breath

    • Provides a summary statement and reiterates the need for a strong understanding of the different networking
    • principles and concepts as well as the numerous technology and applications options for different contexts.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Transport Layer - Chapter 3 PDF

    Description

    Test your understanding of TCP flow control and connection management with this quiz. It covers essential concepts such as buffer space communication and the RcvBuffer role in TCP communication. Prepare to dive into the intricacies of the TCP handshake and demultiplexing.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser