NETWORK BORDER PATROL TO PREVENT CONGESTION COLLAPSE

NETWORK BORDER PATROL TO PREVENT

CONGESTION COLLAPSE

INTRODUCTION

NBP entails the exchange of feedback between routers at the borders of a network in order to detect and restrict unresponsive traffic flows before they enter the network, thereby preventing congestion within the network.

DRAWBACKS OF EXISTING SYSTEM (ATM)

Packets are buffered in the routers present in the network which causes Congestion collapse from undelivered packets arises when bandwidth is continuously consumed by packets that are dropped before reaching their ultimate destinations.

Retransmission of undelivered packets is required to ensure no loss of data.

Unfair bandwidth allocation arises in the Internet due to the presence of undelivered packets.

ADVANTAGES OF PROPOSED SYSTEM

Buffering of packets in carried out in the edge routers rather than in the core routers .

The packets are sent into the network based on the capacity of the network and hence there is no possibility of any undelivered packets present in the network.

Absence of undelivered packets avoids overload due to retransmission.

Fair allocation of bandwidth is ensured.

Project Modules:-

Module 1:- SOURCE MODULE.

Module 2:-INGRESS ROUTER MODULE.

Module 3:- ROUTER MODULE.

Module 4:- EGRESS ROUTER MODULE.

Module 5:- DESTINATION MODULE

DATA FLOW DIAGRAM

Source

Source

Source

Destination

IngressRouter

Router EgressRouter

Destination

Destination

BackwardFeedback

BackwardFeedback

SOURCE MODULE:

Input Parameters:Source Machine Name is retrieved from the OS.Destination Machine Name is typed by User.Message is typed by User.

Output Parameters:Data Packets.

INGRESS MODULE

Input Parameters:Data Packets from Source Machine.Backward feedback from the Router.

Output Parameters:Data Packets.Forward feedback.

RATE CONTROL ALGORITHM

on arrival of BF packet p from egress router eif (p.asynchronous == FALSE) e = cur_time - p.timestamp;if (e.currentRTT < e.baseRTT) e.baseRTT = e.currentRTT;deltaRTT = e.currentRTT - e.baseRTT;RTTElapsed=(CurrentTime-LastFeedbacktime)/currentTime; for each flow f listed in p f.mrc = min (MSS / e.currentRTT, f.egress_rate / MF); if (f.phase == SLOW_START) if (deltaRTT * f.ingress_rate < MSS * e.hopcount) f.ingress_rate = f.ingress_rate * 2^RTTElapsed; else f.ingress_rate = f.egress_rate - f.mrc;

ROUTER MODULE

Input Parameters:

Data Packets from Ingress Machine.Forward feedback from the Router or Ingress Router.Backward feedback from the Router or Egress Router.Hop count.Output Parameters:

Data Packets.Forward feedback. Incremented Hop count.Backward feedback.

EGRESS MODULE

Input Parameters:Data Packets from Router.Forward feedback from the Router.

Output Parameters:Data Packets.Backward feedback

TSW ALGORITHM

Initially:

Win_length = constant;

Avg_rate = connections target rate;

T_front= 0;

Upon each packet arrival:

Bytes_in_TSW = Avg_rate * Win_length;

New_bytes= Bytes_in_TSW + pkt_size;

Avg_rate = New_bytes / (now – T_front + Win_length);

T_front = now;

DESTINATION MODULE

Message received from the egress router will be stored in the corresponding folder as a text file depends upon

the Source Machine Name.

REFERENCE

Network Border Patrol: Preventing Congestion Collapse in the Internet

EEE/ACM Transactions on Networking (TON)

Volume 12 ,  Issue 1  (February 2004)

ISSN:1063-6692

http://netresearch.ics.uci.edu/Previous_research_projects/NBP/paper.html