Sapthagiri College Of Engineering

Department of Information science and EngineeringA

Project on

Sliding Window Congestion Control For TCP Based Network Communication

Guided by: Submitted by:

Gayathri R. Naveen Kumar L.(1SG08IS031)

Rakesh H.C.(1SG08IS045)

Ravichandran K.(1SG09IS406)

Suhas S.(1SG09Is408)

CONTENT

• Introduction• Objective of project• Scope of project• Literature survey• Problem definition• Existing system• Proposed system• Requirement specification• Risk factor• Conclusion• Bibliography

INTRODUCTION

• Transmission Control Protocol (TCP) carries internet traffic, to deliver data reliably across the network.

• Effective network use depends on how TCP based application cooperates with other applications.

• TCP do not rely on any kind of explicit signaling from the network.

• Since TCP works over the IP network, which provides service for delivering packets across the network.

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Introduction contd.

• The key feature of TCP: reliable, bi-directional, virtual channel between any two kind hosts on the internet.

• TCP standard specifies a sliding window based flow control.

OBJECTIVES

• Congestion control to resolve congestion collapse.

• The available bandwidth was effectively used by the proposed algorithm.

• Techniques allows sender to detect loss events, congestion state and route changes.

• Effectively uses the available network resources in different environments.

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SCOPE OF PROJECT

• Used in wired, wireless, high speed, long delay network based communication mechanism.

• It provides Quality of services(QOS) functionality on the network.

• Different mechanisms to detect the high priority data transfer.

• Using the network resource error prone (wireless), safe transmission path (wired) can be isolated.

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LITERATURE SURVEY

• Initial TCP(RFC793)• Fine with less number of

network resource• congestion collapse.

• TCP Tahoe• Slow start• Congestion avoidance

• TCP dual• Queuing delay• Slow start rate.

• TCP Reno• Fast recovery• Retransmission took lot of

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• TCP new Reno• Special state variables.

• Detects and retransmit only one packet.

• TCP sack• Receiver send information of selected block.

• Does not differentiate between wireless loss and congestion loss.

• TCP fack• Handles flow control and rate control efficiently.

• Packet reordering.

• TCP Vegas• Estimates buffer size.

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• TCP Vegas+• Employs bottleneck estimation.

• Transition to aggressive state.

• TCP Veno• Early detection of congestion.

• No fairness between this and Reno.

• Sliding Window• Data structure maintained by sender & receiver.

• Helps to overcome the problem of packet loss.

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Literature Survey on Language:

Java

Platform independence

Compiled and interpreted

Byte Code

JVM(Java Virtual Machine)

Java API

Literature Survey contd.

PROBLEM DEFITION

• Several proposal techniques relay on packet loss to detect network limit has been reached.

• Proposals focused on environments where packets are frequently reordered.

• Basic congestion control principle provide a simple traffic prioritizing feature.

• Aim to solve poor utilization of high speed or long delay of network channels by TCP.

• sliding window(buffers) maintained by sender and receiver helps to solve the congestion collapse.

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EXISTING SYSTEM

• The standard requires receivers to report the sequence number of last in-order delivered data packets each time a packet is received, even if received out of order.

• If sender sees several Acknowledgement carrying the same sequence number(duplicate ACKs), it can be sure that network has failed to deliver some data.

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PROPOSED SYSTEM

• The proposed solution mainly focus on eliminating the phenomenon of congestion collapse.

• Problems of effectively using the available network resources.

• Loss-based and delay-based techniques to estimate the congestion state in network.

• Techniques to detect packet losses quickly.

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Modules used in proposed system

1. TCP host-to-host network module• Techniques that allows sender to detect loss events,

congestion state, loss rate, congestion level.

2. Congestion collapse module• Successful delivery of packets without being congested.• If flow control limit is less than congestion control limit

then it leads to congestion.

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3. Congestion Avoidance and Packet Recovery module

• Avoids the packet loss that occur mainly due to congestion.

• Packet loss treated as request to retransmit the data to achieve the packet recovery.

4. Calculation of RTO & RTT module

• Retransmission Timeout(RTO) is estimated properly in order to make the efficient utilization of network resource.

• Round-Trip Time (RTT) is estimated as time interval for sending the lost packet.

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REQUIREMENT SPECIFICATION

Functional Requirements• Congestion control

• Low packet loss

• Efficient use of available network resources.

• High scalability.

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REQUIREMENT SPECIFICATION(contd.)

Non-functional Requirements

Hardware Requirement• Operating system: Windows XP• Processor: Pentium 3.0 GHz or higher• Ram: 512mb or more• Hard drive: 10 GB or moreSoftware Requirement• Operating system : Windows XP Professional• Front End: Java Technology• Tool: Eclipse 3.3

 

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REQUIREMENT SPECIFICATION(contd.)

Software interfaces:• Application:• Software:Communication interface:• Client device interacts with the server pc

through GSM modem.• Hospital(client) pc interacts with the server pc

through LAN.

RISK FACTOR

• Initial TCP specification is designed to avoid overflow in input buffers at receiver end.

• If the Sliding Window is too large there is a high probability of packet loss.

• TCP should be able to recover the packet loss in the timely fashion.

• If protocol is unaware of network resources, it leads to the congestion collapse.

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CONLUSION

• Objective of the project.• How it is beneficial to the society.• Comparison between existing and proposed system.• Significance of the project.

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BIBLIOGRAPHY

• J.Postel, RFC793-Transmisson control protocol-1981.

• J.Widmar, R.Denda and M.Mauve, A survey on TCP friefndly congestion control, IEEE/ACM Trans.Net Vol.5 Dec-1997.

• lasr.cs.ucla.edu/afanasyev/data/files/Afanasyev/Host-to-host congestion control for TCP.pdf

• IEEE communication surveys and tutorials, 1553-877x/10/$25.00@2010

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Thank You