Computer Networks Chapter 03
53 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Qual es le function del de-multiplexing in le contextu del transport layer?

  • Determinar le protocol de transport a usar.
  • Assignar datagrammas IP a l'application correcte. (correct)
  • Modificar le formato de un segmento TCP.
  • Combinare segmentos de diferentes aplicaciones.

    • Quo es un aspect del connessione-less demultiplexing?

  • Le datagrammas IP non includere source IP.
  • Le socket es construite con un port local specific. (correct)
  • Le UDP segment non porta information de header.
  • Hic, le host non necessita de un address de destination.

    • Qual es le information necessaria in un datagramma IP pro le de-multiplexing?

  • Un code de controle de erro.
  • Le nombre total de datagrammas.
  • Le tamanho static del segmento.
  • Le porta de source e destination. (correct)

    • Qual es le principal differenza inter multiplexing e de-multiplexing?

    <p>Multiplexing combina diferentes aplicaciones, de-multiplexing non.</p> Signup and view all the answers

    Quo debe esser specificate quando se crea un datagramma pro un UDP socket?

    <p>Le destination IP e port.</p> Signup and view all the answers

    Qual es le principal differente inter TCP e UDP?

    <p>TCP offre delivery in ordine, enquanto UDP non lo face.</p> Signup and view all the answers

    Qual caracteristica non es supportate per le protocollo UDP?

    <p>Garantias de retardos</p> Signup and view all the answers

    Que significa multiplexing in le contesto del transport layer?

    <p>Delivery de messages a plure sockets.</p> Signup and view all the answers

    Qual es le principale responsabilitate del demultiplexing?

    <p>Utilizar information del header pro deliverar a le socket correcte.</p> Signup and view all the answers

    Qual es un service non disponibile in le protocollo UDP?

    <p>Garantias de banda</p> Signup and view all the answers

    Como se determina a qual application le message es deliverate?

    <p>Per le header information del message.</p> Signup and view all the answers

    Qual es un desvantaggio de usar UDP comparate con TCP?

    <p>UDP non provide control de congestione.</p> Signup and view all the answers

    Que protocollo usa congestion control?

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

    Qual es le function del transmission control protocol?

    <p>Facer delivery in ordine e reliable.</p> Signup and view all the answers

    Qual es le rol de un socket in le transport layer?

    <p>Identificar le application pro le message sendite.</p> Signup and view all the answers

    Qual es le funzione de rdt_send()?

    <p>Invia datos al livello superiur</p> Signup and view all the answers

    Qual es le principale differentia inter rdt e udt?

    <p>rdt es un protocollo reliable, udt non lo es</p> Signup and view all the answers

    Qual es le rol de deliver_data() in le protocollo rdt?

    <p>Leva datos al livello superiur</p> Signup and view all the answers

    Que tipo de transfer es considerate durante le sviluppo initial del protocollo rdt?

    <p>Transfer unidirectional de datos</p> Signup and view all the answers

    Qual es le effecto de un canale unreliable in le protocollo rdt?

    <p>Creara necessitate de um exito in communication</p> Signup and view all the answers

    In le contexto del protocollo rdt, qual es le funzione de rdt_rcv()?

    <p>Leva un pacchetto quando ille arriva al latere receiver</p> Signup and view all the answers

    Qual es le evenimento importante que occurre durante le communication entre le sender e le receiver?

    <p>Le information de control flue in ambes directiones</p> Signup and view all the answers

    Qual protocollo es primarily responsable pro le transfer de datos in le sender-side?

    <p>rdt_send()</p> Signup and view all the answers

    Qual es le tempo de transmission de un pacco de 8000 bits in un canale con una taxa de transmission de 10 bits/sec?

    <p>8 microsecs</p> Signup and view all the answers

    In le protocol rdt 3.0, como es calculato le tempo total de transmission, Usender?

    <p>RTT + L / R</p> Signup and view all the answers

    Quo es le problema principal del protocol rdt 3.0?

    <p>Le protocol limita le performance del infrastructura subjacente</p> Signup and view all the answers

    Quale modificationes es necessarie pro implementar pipelining in un protocol?

    <p>Aumentar le numero de sequencias e buffering</p> Signup and view all the answers

    Como le pipelining afecta le utilizatio del canale?

    <p>Le utilizatio incrementa per un factor de 3</p> Signup and view all the answers

    Qual es le objetivo del protocollo NAK-free rdt2.2?

    <p>Confirmar solo le ultimi packet ricevuti per medio de ACKs.</p> Signup and view all the answers

    Qual es le secuencia de eventos in un scenario de rdt 3.0?

    <p>Le primo bit de pacco es transmitte, sequite per le reception de le ACK</p> Signup and view all the answers

    Como le sender determina si un packet ha esset ricevute correctemente?

    <p>Per medio de un checksum.</p> Signup and view all the answers

    Que significa 'time to transmit packet into channel' in le contexto de transmission de datos?

    <p>Le tempo necessarie pro le packet pro viajar al recipiente</p> Signup and view all the answers

    Quo significa 'retransmit current pkt' in le contexto de duplicato ACKs?

    <p>Re-inviar le packet actuale al sender.</p> Signup and view all the answers

    In le context de pipelining, qual es le significato de 'in-flight'?

    <p>Paccos que non ha essite acknowledge</p> Signup and view all the answers

    Qual es le resultat de un errore in un packet ricevute?

    <p>Le receiver manda un NAK al sender.</p> Signup and view all the answers

    Qual es le assumption del canal in rdt3.0?

    <p>Le packets pote esser perdite.</p> Signup and view all the answers

    Qual es le consequenza de un packet con un sequenzia corrottato?

    <p>Le receiver savera que le packet non pote esser corrette.</p> Signup and view all the answers

    Qual es le rol de le checksum in le transmission de packet?

    <p>Determinar si un packet es corrottato.</p> Signup and view all the answers

    Qual es le differentia inter rdt2.1 e rdt2.2?

    <p>rdt2.1 usa solo NAKs, rdt2.2 solo ACKs.</p> Signup and view all the answers

    Quo es le function principale del checksum in UDP?

    <p>Pro detectar errores in le transmission.</p> Signup and view all the answers

    Quid ocurre si un carryout emerge durante le addition de inteiros 16-bit?

    <p>Il debe esser addite al summa resultante.</p> Signup and view all the answers

    Qual es le principal limitation del checksum internet?

    <p>Es incapace de garantir un transfert reliable de datos.</p> Signup and view all the answers

    Quid caracteriza le transport de datos reliable?

    <p>Una abstraction de service reliable pro le transfer.</p> Signup and view all the answers

    Quo determina le complexitate del protocollo de transferencia de datos reliable?

    <p>Le caracteristicas del canal unreliable.</p> Signup and view all the answers

    Quo es le statu supports del sender e receiver in le protocollo de transferencia?

    <p>Le sender e receiver non cognosce le statu del altere.</p> Signup and view all the answers

    Quo es le resultat del addition de 16-bit se le bits ha flipado ma le checksum remane identic?

    <p>Le checksums non detecta errores in stile simile.</p> Signup and view all the answers

    Quo es le resultato de un protocoll de transport non reliable?

    <p>Le transmission poterea perder, corromper o reorderar datos.</p> Signup and view all the answers

    Quo es un exemplo de multiplexing in le layer de transport?

    <p>Stabilir plures connexiones simultaneamente.</p> Signup and view all the answers

    Qual e le principale differenita inter TCP e UDP?

    <p>TCP garantisce le delivery de messages, UDP non.</p> Signup and view all the answers

    Quo necessitate le servizio reliable durante e transfer de datos?

    <p>Pro evitar le perdas o corruption de datos.</p> Signup and view all the answers

    Quo non es un characteristic del protocolo UDP?

    <p>Verifica de erres.</p> Signup and view all the answers

    Qual es le beneficio de un protocollo reliable in le transmission de datos?

    <p>Assegura que le data es recte e in ordine.</p> Signup and view all the answers

    Quale statement reflecte le razon de usar checksums?

    <p>Detection de modification accidentale in le datos.</p> Signup and view all the answers

    Study Notes

    Course Information

    • Course Title: Computer Networks
    • Course Code: CENG305
    • University: Izmir Katip Celebi University
    • Semester: Fall 2024-2025
    • Chapter: 03
    • Instructor: H. Burak Akyol, Ph.D.
    • Textbook: Computer Networking: A Top-Down Approach by Jim Kurose and Keith Ross

    Transport Layer: Overview

    • Goal: Understand principles behind transport layer services.
    • Services Include:
      • Multiplexing
      • Demultiplexing
      • Reliable data transfer
      • Flow control
      • Congestion control
    • Protocols:
      • Learn about Internet transport layer protocols.
      • UDP: Connectionless transport
      • TCP: Connection-oriented reliable transport
      • TCP congestion control

    Transport Layer: Roadmap

    • Transport-layer services
    • Multiplexing and demultiplexing
    • Connectionless transport: UDP
    • Principles of reliable data transfer
    • Connection-oriented transport: TCP
    • Principles of congestion control
    • TCP congestion control

    Transport Services and Protocols

    • Provide logical communication between application processes running on different hosts.
    • Transport protocols actions in end systems:
      • Sender: Breaks application messages into segments, passes to network layer.
      • Receiver: Reassembles segments into messages, passes to application layer.
    • Two transport protocols available to Internet applications:
      • TCP
      • UDP

    Transport vs. Network Layer Services and Protocols

    • Transport layer: Communication between processes. Relies on and enhances network layer services.
    • Network layer: Communication between hosts.

    Transport Layer Actions

    • Sender:
      • Receives an application-layer message
      • Determines segment header fields values
      • Creates segment
      • Passes segment to IP layer.
    • Receiver:
      • Receives segment from IP layer
      • Checks header values
      • Extracts application-layer message
      • Demultiplexes message up to application via socket

    Two Principal Internet Transport Protocols

    • TCP: Transmission Control Protocol
      • Reliable, in-order delivery
      • Congestion control
      • Flow control
      • Connection setup
    • UDP: User Datagram Protocol
      • Unreliable, unordered delivery
      • No-frills extension of "best-effort" IP
      • Services not available: delay guarantees, bandwidth guarantees

    Chapter 3: Roadmap

    • Transport-layer services
    • Multiplexing and demultiplexing
    • Connectionless transport: UDP
    • Principles of reliable data transfer
    • Connection-oriented transport: TCP
    • Principles of congestion control
    • TCP congestion control

    Multiplexing/Demultiplexing

    • Multiplexing (as sender): Handles data from multiple sockets, adds transport header (later used for demultiplexing)
    • Demultiplexing (as receiver): Uses header info to deliver received segments to the correct socket

    UDP: User Datagram Protocol

    • "No frills," "bare bones"
    • Internet transport protocol; "best effort" service; UDP segments may be: lost, delivered out-of-order to app.
    • Connectionless
    • No handshaking between sender and receiver
    • Each UDP segment handled independently from others

    UDP: Use Cases

    • Streaming multimedia apps (loss tolerant, rate sensitive)
    • DNS
    • SNMP (Simple Network Management Protocol)
    • HTTP/3 (if needed reliability and congestion control are added at application layer)

    UDP: User Datagram Protocol [RFC 768]

    • Protocol intended to provide a datagram mode of communication with minimal protocol mechanism. Delivery and duplicate protection are not guaranteed.
    • This protocol assumes the use of the Internet protocol (IP)
    • Format includes source port, destination port, length, and checksum fields.

    UDP: Transport Layer Actions

    • Sender Actions:
      • Passes an application-layer message to the transport layer.
      • Determines UDP segment header values.
      • Creates UDP segment.
      • Passes segment to IP layer.
    • Receiver Actions:
      • Receives segment from IP layer.
      • Checks UDP checksum header value
      • Extracts application-layer message
      • Demultiplexes message up to application via socket

    UDP Segment Header

    • Includes source port, destination port, length, and checksum.

    UDP Checksum

    • Goal: Detect errors (e.g., flipped bits) in transmitted segments.
    • Sender: Treats UDP segment contents (including header and IP addresses) as a sequence of 16-bit integers; computes checksum (one's complement sum) and puts it in UDP checksum field.
    • Receiver: Computes checksum of received segment; checks if computed checksum equals checksum field value.

    Internet Checksum

    • Goal: detect errors.
    • Sender: treats contents of UDP segment, computes the checksum, and places the checksum field into the segment.
    • Receiver: computes the checksum, checks if the computed checksum equals checksum field value.

    Principles of Reliable Data Transfer

    • Abstraction: Sending and receiving processes send data over a "reliable channel."
    • Complexity: Depends on characteristics of the unreliable channel.

    Reliable Data Transfer (RDT) Protocol: Interfaces

    • RDT functions: rdt_send(data), deliver_data(data)
    • Bi-directional communication over an unreliable channel

    Reliable Data Transfer: Getting Started

    • Incrementally develop sender and receiver sides of reliable data transfer protocol (RDT)

    RDT 1.0: Reliable Transfer over a Reliable Channel

    • Underlying channel is perfectly reliable; no bit errors or packet loss.

    RDT 2.0: Channel with Bit Errors

    • Underlying channel may flip bits in packets.
    • Receiver uses checksums to detect bit errors.

    RDT 2.0: FSM Specifications

    • Defining states and transitions for sender and receiver FSMs (Finite State Machines)

    RDT 2.0: Operations with no errors

    • Sender sends data, receiver acknowledges (ACKs) successful reception

    RDT 2.0: Corrupted Packet Scenarios

    • Sender resends data when a corrupted packet is detected
    • Receiver discards packets that are duplicates.

    RDT 2.0 has a fatal flaw

    • Sender does not know what happened at receiver if the ACK or NAK packet is corrupted
    • Possible duplicate packets

    RDT 2.1: Handling Garbled ACK/NAKs

    • Sender and receiver design include error checking and retransmission mechanisms.
    • Improved error handling by incorporating sequence numbers.

    RDT 2.2: NAK-Free Protocol

    • Achieves similar functionality to RDT 2.1 but uses only ACKs for confirmation.
    • Receiver must explicitly include the sequence number of the packet being acknowledged.

    RDT 2.2: Sender and Receiver Fragments

    • Sender and receiver implement fragments.

    RDT 3.0: Channels with Errors and Loss

    • Underlying channel may also lose packets
    • Use checksums, sequence numbers, and retransmissions

    RDT 3.0: sender waits "reasonable" amount of time for ACK

    • if ACKs are not received, retransmit

    RDT 3.0 Sender

    • includes a timer mechanism to interrupt operation after a reasonable amount of time

    RDT 3.0 in Action

    • Diagrammatic illustrations of possible scenarios (no loss, packet loss, ACK loss, etc.)

    RDT 3.0 Stop-and-Wait Operation

    • Performance analysis
    • Utilization calculations

    RDT 3.0 Pipelined Protocols Operation

    • Illustrates pipelined protocols which allow multiple unacknowledged packets to be sent and received.

    Pipelining: Increased Utilization

    • Pipelining dramatically increases the utilization level compared to stop-and-wait protocols.

    Studying That Suits You

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

    Quiz Team

    Related Documents

    CENG305 Computer Networks Lecture Notes PDF

    Description

    ingilizce quiz lütfen

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser