Protocol for Noiseless > Simplest protocol > Stop and Wait Protocol

1. PRESENTER
S:
SHIEKH ALI ZAIN (2017-CS-052)
MOHTASHIM SIDDIQUI(2017-CS-048)
ALINA NAEEM(2017-CS-044)

2. PROTOCOLS OF
NOISELESS
SIR SYED UNIVERSITY OF ENGINEERING &
TECHNOLOGY

3. “WHAT WE KNOW IS A DROP,
WHAT WE DON'T KNOW IS AN
OCEAN”
ISAAC NEWTON

4. TODAY’S DISCUSSION
• INTRODUCTION
• SIMPLEST PROTOCOL
• STOP & WAIT PROTOCOL
• ADVANTAGES
• DISADVANTAGES
• CONCLUSION

5. PROTOCOLS FOR
NOISELESS CHANNELS
SIMPLEST STOP & WAIT

6. WHAT IS A PROTOCOL?
• The set of rules and regulations is called a Protocol.
• That provide smooth and reliable transmission of frames
between nodes
• In networking, a frame is a unit of data. Frames also help
to determine how data receivers interpret a stream of data
from a source.
• Nodes are devices or data points on a larger network.

7. WHAT ARE NOISELESS(ERROR-FREE)
CHANNELS
• Noiseless channels are the ideal channel in which no
frames are lost, duplicated, or corrupted.
• We will introduce two protocols for this type of channel:
• The first is a protocol that does not use flow control
(Simplest Protocol)
• the second is the one that does (Stop-and-Wait Protocol).

8. SIMPLEST PROTOCOL
• It is a unidirectional protocol in which data
frames are traveling in only one direction
from the sender to receiver.
• The receiver can immediately handle any
frame it receives with a processing time
that is small enough to be negligible.
• The sender sends a sequence of frames
without even thinking about the receiver.
To send three frames, three events occur at
the sender site and three events at the
receiver site.
flow diagram of Simplest protocol

9. STOP & WAIT PROTOCOL
• The sender sends one frame, stops until it receives
agreement the receiver (okay to go ahead), and then
sends the next frame.
• We still have unidirectional communication for data
frames, but auxiliary ACK frames (simple tokens of
acknowledgment) travel from the other direction.
• We add flow control (ACK) to our previous protocol.

10. • The sender sends one frame and
waits for feedback from the
receiver. When the ACK arrives,
the sender sends the next frame.
Note that sending two frames in
the protocol involves the sender in
four events and the receiver in
two events.
Flow diagram of stop & wait
protocol

11. • Simplest Protocol

12. • Simplest Protocol
• Stop-and-Wait Protocol

13. ADVANTAGES
SIMPLEST PROTOCOL:
• The transmitting (Tx) and receiving (Rx) hosts are always ready
• Works well for small frames.
STOP & WAIT PROTOCOL:
• To improve the efficiency of transmission, multiple frames must be in
transition while waiting for acknowledgment.
• Works well for large frames.

14. DISADVANTAGES
SIMPLEST PROTOCOL:
• Not appropriate for large data .
STOP & WAIT PROTOCOL:
• Frames may be either damaged or lost completely.
• If ACK damaged, transmitter will not recognize it.

15. CONCLUSION
• Network is responsible for transmission of data from one
device to another device. The end to end transfer of data from
a transmitting application to a receiving application involves
many steps, each subject to error. With the error control
process, we can be confident that the transmitted and received
data are identical. Data can be corrupted during transmission.
For reliable communication, error must be detected and
corrected.