Computer Networks Lecture 8: Principles of Reliable Data Transfer
18 Questions
1 Views
3.5 Stars

Computer Networks Lecture 8: Principles of Reliable Data Transfer

This quiz covers the principles of reliable data transfer, including aspects such as flow control, congestion control, and preventing data loss and bit errors. Dr. Dina Fawzy discusses the agenda, principles, and functions related to reliable data transfer in computer networks.

Created by
@ExaltingColosseum

Questions and Answers

What is the primary goal of reliable data transfer?

Preventing data loss and bit errors

What is the role of finite state machines (FSM) in reliable data transfer?

To specify sender and receiver event causing state transition

What does the acronym 'rdt' stand for in the context of reliable data transfer?

Reliable Data Transfer

Which factor is NOT considered part of reliability in data transfer?

<p>Low latency</p> Signup and view all the answers

What is the function of reliable data transfer (rdt) in network protocols?

<p>To ensure data integrity and accuracy</p> Signup and view all the answers

How are state transitions managed in reliable data transfer?

<p>By using finite state machines (FSM)</p> Signup and view all the answers

In the context of reliable transfer over a reliable channel, what is the role of the receiver in recovering from errors?

<p>Sending negative acknowledgements (NAKs) to explicitly tell the sender that a packet had errors</p> Signup and view all the answers

What mechanism is used in rdt2.0 to recover from bit errors in the channel?

<p>Retransmission of the packet on receipt of NAK</p> Signup and view all the answers

What are the new mechanisms introduced in rdt2.0 beyond rdt1.0?

<p>Feedback control messages (ACK,NAK) and error detection</p> Signup and view all the answers

What happens if ACK/NAK is not received in rdt2.0, leading to a fatal flaw?

<p>The sender doesn't know what happened at the receiver</p> Signup and view all the answers

What is the role of checksums in rdt2.0?

<p>To detect bit errors in the packet</p> Signup and view all the answers

What does the sender do on receiving a NAK in rdt2.0?

<p>Retransmits the packet</p> Signup and view all the answers

How does the receiver explicitly tell the sender that a packet was received OK in rdt2.0?

<p>By sending positive acknowledgements (ACKs)</p> Signup and view all the answers

What is the purpose of adding sequence numbers to each packet by the sender?

<p>To prevent possible duplicate handling</p> Signup and view all the answers

In rdt2.0, what does the receiver do on receiving a corrupt packet?

<p>Sends negative acknowledgements (NAKs)</p> Signup and view all the answers

What is the consequence of not receiving ACK/NAK, resulting in a fatal flaw in rdt2.0?

<p>The sender doesn’t know what happened at the receiver.</p> Signup and view all the answers

What is done when a corrupt packet is received in rdt2.0?

<p>The sender sends negative acknowledgements (NAKs).</p> Signup and view all the answers

What is used to detect bit errors in rdt2.0?

<p>The checksums created for each packet.</p> Signup and view all the answers

Study Notes

Reliable Data Transfer (RDT)

  • The primary goal of reliable data transfer is to ensure that data is delivered correctly and in the correct order over a communication channel.

Finite State Machines (FSM)

  • Finite State Machines (FSM) play a crucial role in reliable data transfer by managing the sender's and receiver's states to ensure error-free data transfer.

RDT Acronym

  • RDT stands for Reliable Data Transfer.

Factors Not Considered in Reliability

  • Human factors are NOT considered part of reliability in data transfer.

Function of RDT in Network Protocols

  • The function of reliable data transfer (RDT) in network protocols is to provide error-free data transfer between devices.

State Transitions in RDT

  • State transitions in reliable data transfer are managed using Finite State Machines (FSM), which track the sender's and receiver's states.

Error Recovery in Reliable Channel

  • In the context of reliable transfer over a reliable channel, the receiver plays a crucial role in recovering from errors by detecting and correcting errors.

Error Recovery Mechanism in RDT2.0

  • In RDT2.0, the mechanism used to recover from bit errors in the channel is checksums.

New Mechanisms in RDT2.0

  • The new mechanisms introduced in RDT2.0 beyond RDT1.0 are error detection and correction using checksums and acknowledgement packets (ACK/NAK).

Fatal Flaw in RDT2.0

  • If ACK/NAK is not received in RDT2.0, it leads to a fatal flaw, resulting in the sender retransmitting the packet indefinitely.

Checksums in RDT2.0

  • The role of checksums in RDT2.0 is to detect bit errors in the channel.

Sender's Action on Receiving NAK

  • On receiving a NAK, the sender retransmits the packet.

Receiver's Action on Receiving Packet

  • The receiver explicitly tells the sender that a packet was received OK by sending an ACK packet.

Purpose of Sequence Numbers

  • The purpose of adding sequence numbers to each packet by the sender is to ensure that packets are delivered in the correct order.

Receiver's Action on Corrupt Packet

  • In RDT2.0, the receiver discards the corrupt packet and sends a NAK to the sender.

Consequence of Not Receiving ACK/NAK

  • The consequence of not receiving ACK/NAK, resulting in a fatal flaw in RDT2.0, is the sender retransmitting the packet indefinitely.

Action on Corrupt Packet

  • When a corrupt packet is received in RDT2.0, the receiver discards the packet and sends a NAK to the sender.

Error Detection in RDT2.0

  • Checksums are used to detect bit errors in RDT2.0.

Studying That Suits You

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

Quiz Team

More Quizzes Like This

Use Quizgecko on...
Browser
Browser