This ppt presents the novel algorithm for congestion avoidance called Network Bottleneck Avoider (NBA). NBA entails the exchange of feedback between routers at the borders of a network.

1. Network Bottleneck Avoidance
using Edge Routers
Presented By:
Ankur Singhal
Mayank Manchanda

2. OUTLINE
 Introduction
 Current Scenario
 Problem Statement
 Solution Approach
 Feasibility Study
 Scope
 Existing System
 Proposed System
 Findings and Conclusion
 Future Work

3. INTRODUCTION
 The Internet’s excellent scalability and robustness result in part
from the end-to-end nature of Internet congestion control. End-
to-end congestion control algorithms alone, however, are
unable to prevent the congestion collapse and unfairness
created by applications that are unresponsive to network
congestion.
 The fundamental philosophy behind the Internet is expressed by
the scalability argument- no protocol, mechanism, or service
should be introduced into the Internet if it does not scale well. A
key corollary to the scalability argument is the end-to-end
argument: to maintain scalability, algorithmic complexity
should be pushed to the edges of the network whenever
possible.

4. CURRENT SCENARIO
 There is a need for faster data transfer without the
loss of packet while transmission either through
congestion, communication channel failure or
node failure.
 Users don’t want an overhead of retransmission of
lost or dropped packets.
 Utilization of maximum bandwidth available to
the systems.

5. PROBLEM STATEMENT
 Congestion collapse from undelivered packets
 Unfair bandwidth allocation to competing
network flows

6. SOLUTION APPROACH
 Compare, at the borders of a network, the rates
at which packets from each application flow are
entering and leaving the network.
 If a flow’s packets are entering the network faster
than they are leaving it, then the network is likely
buffering or, worse yet, discarding the flow’s
packets.
 Ensuring that each flow’s packets do not enter
the network at a rate greater than they are able
to leave the network.
 Using NBA with ECSFQ for allocation of fair
bandwidth.

7. FEASIBILITY STUDY
 TECHNICAL REQUIREMENTS
 Advanced Java
 Socket Programming
 File Concepts
 Threads.
 ECNOMICAL REQUIREMENTS
 Proposed system is cheaper
 Easily adaptable for both user and developer.
 OPERATIONAL REQUIREMENTS
 Message sending
 Routing the packet’s
 Controlling the packet flow
 Avoids packet loss.

8. HARDWARE REQUIREMENTS
The minimum configuration required to run
this project are:
 Main processor : Pentium III (or) IV
 RAM : 128MB
 Hard Disk : 10MB
 Clock Speed : 550 MHZ
 System Bus Speed : 400 MHz
 Cache RAM : 256 KB

9. SOFTWARE REQUIREMENTS
 Language : JDK1.7 & Above.
 Front End Design : Swing CONCEPTS
 Operating System : Windows XP and higher version.

10. SCOPE OF THE PROJECT
 Network Bottleneck Avoider entails the exchange
of feedback between routers at the borders of a
network
 Restrict unresponsive traffic flows
 Prevents congestion within the network.

11. EXISTING SYSTEM
 Congestion collapse.
 Retransmission.
 Unfair bandwidth allocation
 core-stateless fair queuing
 WFQ (Waited Fair Queuing) not sufficient
for avoiding congestion

12. PROPOSED SYSTEM
 Buffering of packets is carried out in the
edge routers
 No possibility of any undelivered packets
present in the network
 Fair allocation of bandwidth is ensured

13. MODULE ALLOCATION
 Module 1
SOURCE MODULE.
 Module 2
INGRESS ROUTER MODULE.
 Module 3
ROUTER MODULE.
 Module 4
EGRESS ROUTER MODULE.
 Module 5
DESTINATION MODULE

14. DATA FLOW DIAGRAM
Forward Forward
Feedback Feedback
Source
Source
Source
Destination
InRouter
Router
Router OutRouter
Router
Destination
Destination
Backward
Feedback
Backward
Feedback

15. 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.

16. SOURCE DATA FLOW
DIAGRAM
USER INPUT
DESTINATION AND
MESSAGE
PACKET SPLIT
INTO 48 BYTE
SENDING DATA TO
ROUTER
RECEIVING ACK
FROM ROUTER
PACKET RECEIVED IN
ROUER

17. INGRESS MODULE
Input Parameters:
 Data Packets from Source Machine.
 Backward feedback from the Router.
Output Parameters:
 Data Packets.
 Forward feedback.

18. ALGORITHM IMPLEMENTED
 LEAKY BUCKET ALGORITHM

19. TIME SLIDING ALGORITHM
Arrival of the Forward
Feedback at the
OutRouter Router
Start the timer
If Packets are
arrived
Wait until the packet is
forward
Current Packet is
send
Wait until the Packet is
arrived
Yes
No
Acknowledgement is backward
to InRouter
If Packets are
forwarded
Yes
No
If no Packet to
Forwarded
Stop the timer
Yes
Forward the next packet
No

20. 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.

21. DATA FLOW DIAGRAM
ROUTER
USER INPUT
DESTINATION
AND MESSAGE
PACKET SPLIT
INTO 48 BYTE
SENDING DATA
TO ROUTER
RECEIVING ACK
FROM ROUTER
PACKET RECEIVED IN
ROUTER

22. EGRESS ROUTER MODULE
Input Parameters:
 Data Packets from Router.
 Forward feedback from the Router.
Output Parameters:
 Data Packets.
 Backward feedback

23. RATE CONTROL ALGORITHM
If
CurrentRTT<e.b
aseRTT
On arrival of backward feedback packet p from
OutRouter router e
Current RTT =Current Time -p.times tamp
Delta RTT=-Current RTT-
e.base RTT
e.base RTT=Current RTT
RTTs Elapsed= (Current Time-e.last
FeedbackTime)/CurrentRTT
e.last FeedbackTime=Current Time
For each flow f listed in p
Rate Quantum=min (MSS/currentRTT, f.egreesRate/QF)
A
B
True
False

24. f.phase=
CONGESTION_
AVOIDANCE
If
(deltaRTT*f.InRouterRate<MSS*e.h
opcount)
f.InRouter Rate=f.InRouterRate*2^RTTsElapsed
If f.phase
= = CONGESTION_
AVOIDANCE
If
(deltaRTT*f.InRouterRate<MSS*e.h
opcount)
f.InRouterRate=f.InRouter Rate + rate Quantum*RTTsElapsed
f. InRouter Rate=
f.OutRouterRate-
rateQuantum
NEXT
True
True
False
True
False
If f.phase
= = SLOW_START
B A

25. 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.

26. DESTINATION DATA FLOW
DIAGRAM
DESTINATION
RETRIVE THE
ALLOCATED BYTE
COMBINE THE
PACKET IN(48 BYTES)
FINALLY SAVE
THEM IN TEXT FILE

27. FINDINGS
 One flow is a TCP flow generated by an
application that always has data to send
 The other flow is a constant bit rate UDP flow
generated by an application that is unresponsive
to congestion

28. FINDINGS
 Severe congestion collapse using FIFO only

29. FINDINGS
 Moderate congestion collapse using ECSFQ only

30. FINDINGS
 No congestion collapse using NBA with FIFO.

31. CONCLUSION
 NBA is able to prevent congestion collapse from
undelivered packets. NBA ensures at the border
of the network that each flow’s packets do not
enter the network faster than they are able to
leave it.
 Simulation results show that NBA successfully
prevents congestion collapse from undelivered
packets. They also show that, while NBA is unable
to eliminate unfairness on its own, but it can be
seen that it will be able to achieve approximate
global max-min fairness for competing network
flows when combined with ECSFQ, they
approximate global max-min fairness in a
completely core-stateless fashion.

32. FUTURE WORK
 Combining Enhanced Core Stateless Fair
Queuing mechanism With the Network
Bottleneck Avoider to achieve fair allocation of
bandwidth within the link.
 Simulate and compare the performance of NBA
system using multiple routers.
 Examine backward feedback packets from
more than one egress router.
 Determining the most congested ingress to
egress path (i.e., the one with the lowest flow
egress rate)

33. THANK YOU