final ppt 02 april 2012
TRANSCRIPT
-
8/2/2019 Final PPT 02 April 2012
1/14
Presented By:Retaish Wali
Neha Arya
SIMULATION OFDATA LINK LAYERARQ TECHNIQUES
Progress Report
Final Yr Project
-
8/2/2019 Final PPT 02 April 2012
2/14
Introduction
Our project titled Simulation Of Data Link Layer ARQTechniquesis aimed at simulating the actions of datalink layer in controlling the data flow and errors by
Automatic Repeat Request (ARQ) .
About Data Link Layer
Layer-2 of OSI model of networking
Framing
Physical addressing
Error and Flow control
Frame Synchronization
-
8/2/2019 Final PPT 02 April 2012
3/14
-
8/2/2019 Final PPT 02 April 2012
4/14
Resource Requirements
Hardware Specifications :
Processor : 1.6GHz or faster
RAM : 1 GB (32 Bit) or 2 GB (64 Bit) RAM
Hard Disk : 3GB of free spaceResolution : 1024 x 768 or higher
Software Specifications :
Operating System : Windows Environment
Front End : Visual Studio 2010
-
8/2/2019 Final PPT 02 April 2012
5/14
Module Classification
There are three modules in our project
1. Stop and Wait
2. Go Back N3. Selective Repeat
-
8/2/2019 Final PPT 02 April 2012
6/14
1. Stop And Wait
Mechanism of Stop and Wait ARQ technique
1. Sender : STOP after transmitting a single frame & Wait for ACK
2. Receiver : Receive correct frame & Transmit acknowledgment(ACK)
3. Sender : ACK received before timeout : Go to Step 1.
Else
Re-transmit the frame
-
8/2/2019 Final PPT 02 April 2012
7/14
-
8/2/2019 Final PPT 02 April 2012
8/14
2. Go Back N
Mechanism of Go Back N Flow technique
1. Sender : Send no. of frames specified by a Window Size
No wait for ACK
2. Receiver : Transmit acknowledgment(ACK) for correct frame received
Else
Discard frames & transmit Negative ACK (NAK)
3. Sender : Only ACK sreceived: Go to Step 1
Else
Re-transmit the damaged/Lost ACK frame & its followers
-
8/2/2019 Final PPT 02 April 2012
9/14
-
8/2/2019 Final PPT 02 April 2012
10/14
3. Selective Repeat
Mechanism of Selective Repeat Flow technique
1. Sender : Send no. of frames specified by a Window Size
No wait for ACK
2. Receiver : Transmit acknowledgment (ACK) for correct frame received
Else
Discard frames & transmit Negative ACK (NAK)
3. Sender : Only ACK sreceived: Go to Step 1Else
Re-transmit only damaged /Lost ACK frame
-
8/2/2019 Final PPT 02 April 2012
11/14
-
8/2/2019 Final PPT 02 April 2012
12/14
Snapshot
-
8/2/2019 Final PPT 02 April 2012
13/14
Simulation of error/flow technique thus aims at assuring safety intransmitting data.
Selective Repeat has advantage over Go Back N that N-fewer
re-transmissions occur but carries a disadvantage of more complexity at
sender and receiver
Go Back N sends multiple frames equivalent to window size(N)but
single NAK leads to retransmission of N-frames.
Stop and Wait is simple to implement but inefficient due to wastage of
bandwidth in transmitting duplicate frames.
Conclusion
-
8/2/2019 Final PPT 02 April 2012
14/14
QUERIES ?
Thank You