Communication Network

F R A M I N G

A Presentation on

By Th Nanao

7th Semester ECE

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Frames and Framing

Frames Are The Small data Units Created By

Data Link Layer

And The Process Of Creating Frames By The

Data Link Layer Is Known As Framing.

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Communication without FRAMING

UNFRAMED DATAS

“NITMANIPUR”

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SEND!!RECEIVED!

So what FRAMING does is…

NIT Manipur

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Methods of FRAMING

Character Count.

Starting & Ending Characters With Character Stuffing.

Starting & ending Flags With Bit Stuffing.

Physical Layer Coding Violation.

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Character Count

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5 1 2 3 4 5 6 7 8 9 8 0 1 2 3 4 5 6 8 7 8 9 0 1 2 3

Frame 1

5 characters

Frame 2

5 characters

Frame 3

8 characters

Frame 4

8 characters

Starting & Ending Characters With Character Stuffing.

A B C D

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DLE STX A B C D DLE ETX

Data from Network Layer

Start of Frame DATA End of Frame

Starting & ending Flags With Bit Stuffing

01111110 DATA 01111110

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FLAGS

Starting Flag Bit Ending Flag Bit

An example of Bit Stuffing

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011011111111111111110010

011011111111111111110010

011011111011111011111010010

Bits stuffed at the sender

Bits de-stuffed at the receiver

Original data

Physical Layer Coding Violation

This Framing Method Is Used only In those network In which Encoding On The Physical Medium Contain some Redundancy.

Some LANs Encode Each Bit Of Data By using two Physical Bit i.e. Manchester coding is Used.

In this method Bit 1 Is encoded into high-low(10) Pair And Bit 0 Is Encoded Into low-high(01)pair shown in figure.

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Physical Layer Coding Violation

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0 1 10 01

Menchester Encoding

Conclusion

We learned what is framing, why we need it and how to apply

them according to the requirements.

Without framing the data sequence will not be in order.

Without framing we wouldn't be able to view the original

information received.

Framing is the key to Sequential flow of data in its true form.

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Thank You

For ‘any’ doubt visit www.google.com

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