performance analysis of peer-to-peer file transfer network sayantan mitra vibhor goyal 1

Performance Analysisof

Peer-to-Peer File Transfer Network

Sayantan MitraVibhor Goyal

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Napster Architecture

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Your ComputerYour Computer

Directory of FilesDirectory of Files

I want file X

Y has it!

I want fi

le X

Here it is

Update

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Assumptions

• No Concurrent upload and download of files.• No peer leaves the system before completing

the file transfer.• No physical transfer of files; instead a stream

of bytes is transferred.

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Scalability Analysis

• File transfer time.• Dropped Packets.• Handling of File Requests with simultaneous

access demand (Load Balancing).• SHA-1 Mismatch.• Bandwidth Usage.• Latency.

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Scalability Analysis

• File transfer time.• Dropped Packets.• Handling of File Requests with simultaneous

access demand (Load Balancing).• SHA-1 Mismatch.• Bandwidth Usage.• Latency.

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Models used in Experiments

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Server

Peer 1

Peer 2

Peer 3

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Server

Peer 1

Peer 3

Peer 2

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Server

Peer 2

Peer 1

Peer 3

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Server

Peer 3

Peer 2

Peer 1

Peer 6

Peer 5

Peer 4

Peer 9

Peer 8

Peer 7

Peer 12

Peer 11

Peer 10

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File transfer time Analysis

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• Setup– File divided in specified sized chunks.– Sliding window protocol.

• Variations– File Size.– Sliding Window size.– Packet size.

• Observations– The variation in transfer time at the sender and receiver

end, with change in above said parameters.• Regression– Try to find out an equation of regression between the time

of transfer with respect to the above mentioned parameters.

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Dropped Packets Analysis

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• Simulating Network behavior.– Random ACK drop.– Network delay in ACK.

• Parameters– File Size– Packet Size– Window size

• Observations– Number of packets resent due to lost ACKs and their

variations due to change in above said parameters.• Regression– Try to find an equation of regression between the number

of packets to be resent with that of the mentioned parameters.

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To-Do

• Handling of File Requests with simultaneous access demand (Load Balancing).

• SHA-1 Mismatch.• Bandwidth Usage.• Latency.• EMULAB.

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Questions ???

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