International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
Available network bandwidth schema to improve performance in tcp protocolsIJCNCJournal
The TCP congestion control mechanism in standard implementations presents several problems, for
example, large queue lengths in network routers and packet losses, a misleading reduce of the transmission
rate when there are link failures, among others. This paper proposes a schema to congestion control in
TCP protocols, called NGWA, witch is based on the network bandwidth. The NGWA provides information
considering the available bandwidth of the network infrastructure to the endpoints of the TCP connection.
Hence, it helps in choosing a better transmission rate for TCP improving its performance. Simulation
results show superior performance of the proposed scheme when compared to those obtained by TCP New
Reno and standard TCP. A physical implementation in the Linux kernel was performed to prove the correct
operation of the proposal.
Transmission Control Protocol (TCP) is a fundamental protocol of the Internet Protocol Suite. TCP complements the Internet Protocol (IP), therefore it is common to refer to the internet protocol suit as TCP/IP. TCP is used for error detection, detection of packet loss or out of order delivery of data. TCP requests retransmission, rearranges data and helps with network congestion.
Several congestion control algorithms have been developed, over the last years, to improve TCP's performance over various technologies and network conditions.
The purpose of this assignment is to present TCP, network congestion, congestion algorithms and simulate different algorithms in different network conditions to measure their performance. For this assignment's needs, OPNET IT Guru Academic Edition software was used to accomplish the reproduction of projects that have been already published and gave the wanted results.
KALMAN FILTER BASED CONGESTION CONTROLLERijdpsjournal
Facing burst traffic, TCP congestion control algorithms severely decrease window size neglecting the fact
that such burst traffics are temporal. In the increase phase sending window experiences a linear rise which
may lead to waste in hefty proportion of available bandwidth. If congestion control mechanisms be able to
estimate future state of network traffic they can cope with different circumstances and efficiently use
bandwidth. Since data traffic which is running on networks is mostly self-similar, algorithms can take
advantage of self-similarity property and repetitive traffic patterns to have accurate estimations and
predictions in large time scales.
In this research a two-stage controller is presented. In fact the first part is a RED congestion controller
which acts in short time scales (200 milliseconds) and the second is a Kalman filter estimator which do
RTT and window size estimations in large time scales (every two seconds). If the RED mechanism decides
to increase the window size, the magnitude of this increase is controlled by Kalman filter. To be more
precise, if the Kalman filter indicates a non-congested situation in the next large time scale, a magnitude
factor is calculated and given to RED algorithm to strengthen the amount of increase.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
Available network bandwidth schema to improve performance in tcp protocolsIJCNCJournal
The TCP congestion control mechanism in standard implementations presents several problems, for
example, large queue lengths in network routers and packet losses, a misleading reduce of the transmission
rate when there are link failures, among others. This paper proposes a schema to congestion control in
TCP protocols, called NGWA, witch is based on the network bandwidth. The NGWA provides information
considering the available bandwidth of the network infrastructure to the endpoints of the TCP connection.
Hence, it helps in choosing a better transmission rate for TCP improving its performance. Simulation
results show superior performance of the proposed scheme when compared to those obtained by TCP New
Reno and standard TCP. A physical implementation in the Linux kernel was performed to prove the correct
operation of the proposal.
Transmission Control Protocol (TCP) is a fundamental protocol of the Internet Protocol Suite. TCP complements the Internet Protocol (IP), therefore it is common to refer to the internet protocol suit as TCP/IP. TCP is used for error detection, detection of packet loss or out of order delivery of data. TCP requests retransmission, rearranges data and helps with network congestion.
Several congestion control algorithms have been developed, over the last years, to improve TCP's performance over various technologies and network conditions.
The purpose of this assignment is to present TCP, network congestion, congestion algorithms and simulate different algorithms in different network conditions to measure their performance. For this assignment's needs, OPNET IT Guru Academic Edition software was used to accomplish the reproduction of projects that have been already published and gave the wanted results.
KALMAN FILTER BASED CONGESTION CONTROLLERijdpsjournal
Facing burst traffic, TCP congestion control algorithms severely decrease window size neglecting the fact
that such burst traffics are temporal. In the increase phase sending window experiences a linear rise which
may lead to waste in hefty proportion of available bandwidth. If congestion control mechanisms be able to
estimate future state of network traffic they can cope with different circumstances and efficiently use
bandwidth. Since data traffic which is running on networks is mostly self-similar, algorithms can take
advantage of self-similarity property and repetitive traffic patterns to have accurate estimations and
predictions in large time scales.
In this research a two-stage controller is presented. In fact the first part is a RED congestion controller
which acts in short time scales (200 milliseconds) and the second is a Kalman filter estimator which do
RTT and window size estimations in large time scales (every two seconds). If the RED mechanism decides
to increase the window size, the magnitude of this increase is controlled by Kalman filter. To be more
precise, if the Kalman filter indicates a non-congested situation in the next large time scale, a magnitude
factor is calculated and given to RED algorithm to strengthen the amount of increase.
Recital Study of Various Congestion Control Protocols in wireless networkiosrjce
IOSR Journal of Computer Engineering (IOSR-JCE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of computer engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in computer technology. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Comparison of TCP congestion control mechanisms Tahoe, Newreno and VegasIOSR Journals
The widely used reliable transport protocol TCP, is an end to end protocol designed for the wireline
networks characterized by negligible random packet losses. This paper represents exploratory study of TCP
congestion control principles and mechanisms. Modern implementations of TCP contain four intertwined
algorithms: slow start, congestion avoidance, fast retransmit, and fast recovery. In addition to the standard
algorithms used in common implementations of TCP, this paper also describes some of the more common
proposals developed by researchers over the years. We also study, through extensive simulations, the
performance characteristics of four representative TCP schemes, namely TCP Tahoe, New Reno and Vegas
under the network conditions of bottleneck link capacities for wired network
Review of the paper: Traffic-aware Frequency Scaling for Balanced On-Chip Net...Luca Sinico
This work has been done as assignment and as part of the exam of the Distributed Systems course, while attending the Master's Degree in Computer Engineering at University of Padua.
If you find something wrong or not clear, or if you don't agree with me with the work done or the grades of the assessment, please tell me.
Effective Router Assisted Congestion Control for SDN IJECEIAES
Router Assisted Congestion Control (RACC) was designed to improve endto-end congestion control performance by using prior knowledge on network condition. However, the traditional Internet does not provide such information, which makes this approach is not feasible to deliver. Our paper addresses this network information deficiency issue by proposing a new congestion control method that works on the Software Defined Network (SDN) framework. We call this proposed method as PACEC (Path Associativity Centralized Congestion Control). In SDN, global view of the network information contains the network topology including link properties (i.e., type, capacity, power consumption, etc.). PACEC uses this information to determine the feedback signal, in order for the source to start sending data at a high rate and to quickly reach fair-share rate. The simulation shows that the efficiency and fairness of PACEC are better than Transmission Control Protocol (TCP) and Rate Control Protocol (RCP).
Slides der Präsentation von Simeon Bosshard, Citrix, am Citrix Day 2014 von Digicomp.
Das HTML 5 GUI im Release 10.5 des NetScaler ist eine Neuerung, aber nicht die einzige. Erfahren Sie mehr über die wichtigsten Änderungen wie etwa MobileStream, Cisco RISE und ACI Integration sowie die Erweiterungen im Authentication-Bereich. Natürlich kommen die Neuerungen in den Core-Bereichen Loadbalancing, SSL Offloading etc. ebenfalls nicht zu kurz.
Recital Study of Various Congestion Control Protocols in wireless networkiosrjce
IOSR Journal of Computer Engineering (IOSR-JCE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of computer engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in computer technology. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Comparison of TCP congestion control mechanisms Tahoe, Newreno and VegasIOSR Journals
The widely used reliable transport protocol TCP, is an end to end protocol designed for the wireline
networks characterized by negligible random packet losses. This paper represents exploratory study of TCP
congestion control principles and mechanisms. Modern implementations of TCP contain four intertwined
algorithms: slow start, congestion avoidance, fast retransmit, and fast recovery. In addition to the standard
algorithms used in common implementations of TCP, this paper also describes some of the more common
proposals developed by researchers over the years. We also study, through extensive simulations, the
performance characteristics of four representative TCP schemes, namely TCP Tahoe, New Reno and Vegas
under the network conditions of bottleneck link capacities for wired network
Review of the paper: Traffic-aware Frequency Scaling for Balanced On-Chip Net...Luca Sinico
This work has been done as assignment and as part of the exam of the Distributed Systems course, while attending the Master's Degree in Computer Engineering at University of Padua.
If you find something wrong or not clear, or if you don't agree with me with the work done or the grades of the assessment, please tell me.
Effective Router Assisted Congestion Control for SDN IJECEIAES
Router Assisted Congestion Control (RACC) was designed to improve endto-end congestion control performance by using prior knowledge on network condition. However, the traditional Internet does not provide such information, which makes this approach is not feasible to deliver. Our paper addresses this network information deficiency issue by proposing a new congestion control method that works on the Software Defined Network (SDN) framework. We call this proposed method as PACEC (Path Associativity Centralized Congestion Control). In SDN, global view of the network information contains the network topology including link properties (i.e., type, capacity, power consumption, etc.). PACEC uses this information to determine the feedback signal, in order for the source to start sending data at a high rate and to quickly reach fair-share rate. The simulation shows that the efficiency and fairness of PACEC are better than Transmission Control Protocol (TCP) and Rate Control Protocol (RCP).
Slides der Präsentation von Simeon Bosshard, Citrix, am Citrix Day 2014 von Digicomp.
Das HTML 5 GUI im Release 10.5 des NetScaler ist eine Neuerung, aber nicht die einzige. Erfahren Sie mehr über die wichtigsten Änderungen wie etwa MobileStream, Cisco RISE und ACI Integration sowie die Erweiterungen im Authentication-Bereich. Natürlich kommen die Neuerungen in den Core-Bereichen Loadbalancing, SSL Offloading etc. ebenfalls nicht zu kurz.
The Transmission Control Protocol (TCP) is used by the vast majority of applications to transport their data reliably across the Internet and in the cloud. TCP was designed in the 1970s and has slowly evolved since then. Today's networks are multipath: mobile devices have multiple wireless interfaces, datacenters have many redundant paths between servers, and multihoming has become the norm for big server farms. Meanwhile, TCP is essentially a single-path protocol: when a TCP connection is established, the connection is bound to the IP addresses of the two communicating hosts and these cannot change. Multipath TCP (MPTCP) is a major modification to TCP that allows multiple paths to be used simultaneously by a single transport connection. Multipath TCP circumvents the issues mentioned above and several others that affect TCP. The IETF is currently finalising the Multipath TCP RFC and an implementation in the Linux kernel is available today.
This tutorial will present in details the design of Multipath TCP and the role that it could play in cloud environments. We will start with a presentation of the current Internet landscape and explain how various types of middleboxes have influenced the design of Multipath TCP. Second we will describe in details the connection establishment and release procedures as well as the data transfer mechanisms that are specific to Multipath TCP. We will then discuss several use cases for the deployment of Multipath TCP including improving the performance of datacenters and
mobile WiFi offloading on smartphones. All these use cases are key when both accessing cloud-based services or when providing them. We will end the tutorial with some open research issues.
This tutorial was given at the IEEE Cloud'Net 2012 conference in novembrer 2012.
The pptx version containing animations that are not shown here is available from http://www.multipath-tcp.org
The performance of wireless ad hoc networks is impacted significantly by the way TCP reacts to lost packets. TCP was designed specifically for wired, reliable networks; thus, any packet loss is attributed to congestion in the network. This assumption does not hold in wireless networks as most packet loss is due to link failure. In our research we analyzed several implementations of TCP, including TCP Vegas, TCP Feedback, and SACK TCP, by measuring throughput, retransmissions, and duplicate acknowledgements through simulation with ns-2. We discovered that TCP throughput is related to the number of hops in the path, and thus depends on the performance of the underlying routing protocol, which was DSR in our research.
Abstract - The Transmission Control Protocol (TCP) is
connection oriented, reliable and end-to-end protocol that support
flow and congestion control, with the evolution and rapid growth
of the internet and emergence of internet of things IoT, flow and
congestion have clear impact in the network performance. In this
paper we study congestion control mechanisms Tahoe, Reno,
Newreno, SACK and Vegas, which are introduced to control
network utilization and increase throughput, in the performance
evaluation we evaluate the performance metrics such as
throughput, packets loss, delivery and reveals impact of the cwnd.
Showing that SACK had done better performance in terms of
numbers of packets sent, throughput and delivery ratio than
Newreno, Vegas shows the best performance of all of them.
NetWork Design Question2.) How does TCP prevent Congestion Dicuss.pdfoptokunal1
NetWork Design Question
2.) How does TCP prevent Congestion? Dicuss the information identifying congestion in the
network as well as the mechanism for reducing congestion?
Solution
Congestion is a problem that occurs on shared networks when multiple users contend for access
to the same resources (bandwidth, buffers, and queues).
Transmission Control Protocol (TCP) uses a network congestion-avoidance algorithm that
includes various aspects of an additive increase/multiplicative decrease (AIMD) scheme, with
other schemes such as slow-start to achieve congestion avoidance.
The TCP congestion-avoidance algorithm is the primary basis for congestion control in the
Internet.
Congestion typically occurs where multiple links feed into a single link, such as where internal
LANs are connected to WAN links. Congestion also occurs at routers in core networks where
nodes are subjected to more traffic than they are designed to handle.
TCP/IP networks such as the Internet are especially susceptible to congestion because of their
basic connection- less nature. There are no virtual circuits with guaranteed bandwidth. Packets
are injected by any host at any time, and those packets are variable in size, which make
predicting traffic patterns and providing guaranteed service impossible. While connectionless
networks have advantages, quality of service is not one of them.
Shared LANs such as Ethernet have their own congestion control mechanisms in the form of
access controls that prevent multiple nodes from transmitting at the same time.
Identifying:
Congestion is primarily reflected by a conventional user feeling-- slowness. This statement
reflects the change in the network effective flow, that is the time required to transmit an entire
data from one point to another. The effective flow doenot exist as such, it consists in reality of
three seperate indicators:
*Latency:the effective flow is inversely proportional to the latency.
*Jitter:it is latency variation over time, impacts by influencing the flow latency
*Loss Rate:the theoritical bandwidth is inversely proportional to the square root of the loss rate
These Congestion symtoms allow us to rely on objective indicators to characterize it.
Mechanism to reduce congestion:
The standard fare in TCP implementations today has four standard congestion control algorithms
that are now in common use. Their usefulness has passed the test of time.
The four algorithms, Slow Start, Congestion Avoidance, Fast Retransmit and Fast Recovery are
described below. (a) Slow Start
Slow Start, a requirement for TCP software implementations is a mechanism used by the sender
to control the transmission rate, otherwise known as sender-based flow control. This is
accomplished through the return rate of acknowledgements from the receiver. In other words, the
rate of acknowledgements returned by the receiver determine the rate at which the sender can
transmit data. When a TCP connection first begins, the Slow Start algorithm initializes a
.
PERFORMANCE ANALYSIS OF MULTI-PATH TCP NETWORKIJCNCJournal
MPTCP is proposed by IETF working group, it allows a single TCP stream to be split across multiple
paths. It has obvious benefits in performance and reliability. MPTCP has implemented in Linux-based
distributions that can be compiled and installed to be used for both real and experimental scenarios. In this
article, we provide performance analyses for MPTCP with a laptop connected to WiFi access point and 3G
cellular network at the same time. We prove experimentally that MPTCP outperforms regular TCP for
WiFi or 3G interfaces. We also compare four types of congestion control algorithms for MPTCP that are
also implemented in the Linux Kernel. Results show that Alias Linked Increase Congestion Control
algorithm outperforms the others in the normal traffic load while Balanced Linked Adaptation algorithm
outperforms the rest when the paths are shared with heavy traffic, which is not supported by MPTCP.
APNIC Chief Scientist Geoff Huston gives a presentation on Buffers, Buffer Bloat and BBR at NZNOG 2020 in Christchurch, New Zealand, from 28 to 31 January 2020.
IMPACT OF CONTENTION WINDOW ON CONGESTION CONTROL ALGORITHMS FOR WIRELESS ADH...cscpconf
TCP congestion control mechanism is highly dependent on MAC layer Backoff algorithms that
predict the optimal Contention Window size to increase the TCP performance in wireless adhoc
network. This paper critically examines the impact of Contention Window in TCP congestion
control approaches. The modified TCP congestion control method gives the stability of
congestion window which provides higher throughput and shorter delay than the traditional TCP. Various Backoff algorithms that are used to adjust Contention Window are simulatedusing NS2 along with modified TCP and their performance are analyzed to depict the influence of Contention Window in TCP performance considering the metrics such as throughput, delay, packet loss and end-to-end delay
Towards Seamless TCP Congestion Avoidance in Multiprotocol EnvironmentsIDES Editor
In this paper we explore the area of congestion
avoidance in computer networks. We provide a brief overview
of the current state of the art in congestion avoidance and also
list our extension to the TCP congestion avoidance mechanism.
This extension was previously published on an international
forum and in this paper we describe an improved version which
allows multiprotocol support. We list preliminary results
carried out in a simulation environment.
New introduced approach called Advanced Notification
Congestion System (ACNS) allows TCP flows prioritization
based on the TCP flow age and priority carried in the header
of the network layer protocol. The aim of this approach is to
provide more bandwidth for young and high prioritized TCP
flows by means of penalizing old greedy flows with a low
priority. Using ACNS, substantial network performance
increase can be achieved.
Improving Performance of TCP in Wireless Environment using TCP-PIDES Editor
Improving the performance of the transmission
control protocol (TCP) in wireless environment has been an
active research area. Main reason behind performance
degradation of TCP is not having ability to detect actual reason
of packet losses in wireless environment. In this paper, we are
providing a simulation results for TCP-P (TCP-Performance).
TCP-P is intelligent protocol in wireless environment which
is able to distinguish actual reasons for packet losses and
applies an appropriate solution to packet loss.
TCP-P deals with main three issues, Congestion in
network, Disconnection in network and random packet losses.
TCP-P consists of Congestion avoidance algorithm and
Disconnection detection algorithm with some changes in TCP
header part. If congestion is occurring in network then
congestion avoidance algorithm is applied. In congestion
avoidance algorithm, TCP-P calculates number of sending
packets and receiving acknowledgements and accordingly set
a sending buffer value, so that it can prevent system from
happening congestion. In disconnection detection algorithm,
TCP-P senses medium continuously to detect a happening
disconnection in network. TCP-P modifies header of TCP
packet so that loss packet can itself notify sender that it is
lost.This paper describes the design of TCP-P, and presents
results from experiments using the NS-2 network simulator.
Results from simulations show that TCP-P is 4% more
efficient than TCP-Tahoe, 5% more efficient than TCP-Vegas,
7% more efficient than TCP-Sack and equally efficient in
performance as of TCP-Reno and TCP-New Reno. But we can
say TCP-P is more efficient than TCP-Reno and TCP-New
Reno since it is able to solve more issues of TCP in wireless
environment.
Improving Performance of TCP in Wireless Environment using TCP-P
presentation
1. CONGESTION CONTROL AND PACKETCONGESTION CONTROL AND PACKET
REORDERING FOR MULTIPATHREORDERING FOR MULTIPATH
TRANSMISSION CONTROL PROTOCOLTRANSMISSION CONTROL PROTOCOL
By,
Nirnimesh Ghose,
Master of Science,
Department of Electrical Engineering
2. IntroductionIntroduction
• Connections generally had only one path to
transfer data from source to destination.
• With new mobile devices have more than one
connections between the source and destination.
• Newer technology was required to use them at
the same time to improve the throughput like
MultiPath Transmission Control Protocol.
3. MPTCPMPTCP
• Basic idea is that if flows are able to
simultaneously use more than one path through
the network, then they will be more resilient to
problems on particular paths and they will be
able to pool capacity across multiple links.
• These multiple paths might be obtained for
example by sending from multiple interfaces, or
sending to different IP addresses of the same
host, or by some form of explicit path control.
4. MPTCPMPTCP
Main MechanismMain Mechanism
• The Multipath TCP protocol uses new TCP
options to exchange signaling information
between peers:
– MPC (Multipath Capable) is used during the three-way
handshake to establish a MultipathTCP connection.
– DATA FIN is used to inform the remote peer of the
end of data and to close the multipath TCP
connections.
– ADD and REMove address are used to inform the
remote peer of the availability of a new address or to
ask it to ignore an existing one.
5. MPTCPMPTCP
Main MechanismMain Mechanism
– JOIN is used to initiate a new subflow between nodes
already used couple of addresses.
– DSN (Data Sequence Number) is used to map
between the subflow level and the data sequence
space number.
8. MPTCPMPTCP
Congestion ControlCongestion Control
• The following three goals as per IETF draft
capture the desirable properties of a practical
multipath congestion control algorithm:
– Improve Throughput: A multipath flow should perform at least
as well as a single path flow would on the best of the paths
available to it.
– Do no harm: A multipath flow should not take up more capacity
from any of the resources shared by its different paths, than if it
was a single flow using only one of these paths. This guarantees
it will not unduly harm other flows.
– Balance congestion: A multipath flow should move as much
traffic as possible off its most congested paths, subject to
meeting first two goals.
9. MPTCPMPTCP
Congestion ControlCongestion Control
• Uncoupled TCP
– Increase wr by 1/wr per ack on path r.
– Decrease wr by wr/2 per loss event on path r.
• Linked Increase
– Increase wr by α/wr per ack on path r
– Decrease wr by wr/2 per loss event on path r
2
ˆ
ˆ
max
ˆ
=
∑ RTTw
RTT
w
rr r
r
r
r
wα
10. MPTCPMPTCP
Congestion ControlCongestion Control
• Fully Coupled
– Increase wr by 1/w per ack on path r.
– Decrease wr to max(wr - w/b, 1) per loss event on path
r
• RTT Compensator
– Increase wr by min(α/w, 1/wr) per ack on path r.
– Decrease wr to wr/2 per loss event on path r
2
ˆ
ˆ
max
ˆ
=
∑r
r
r
r
r
r
RTT
w
RTT
w
wα
13. MPTCPMPTCP
Packet Reordering TechniquePacket Reordering Technique
• F-RTO Algorithm
– When the retransmission timer expires, retransmit the
segment that triggered the timeout.
– When the first acknowledgement after RTO arrives at
the sender, the sender chooses the following actions
depending in whether the ACK advances the window
or whether it is a duplicate ACK.
• If the acknowledgement advances SND.UNA (send
unacknowledged), transmit up to two new (previously unsent)
segments.
• If the acknowledgment is duplicate ACK, set the congestion
window to one segment and proceed with the conventional
RTO recovery.
14. MPTCPMPTCP
Packet Reordering TechniquePacket Reordering Technique
– When the second acknowledgment after the RTO
arrives, either continue transmitting new data, or start
retransmission with the slow start algorithm,
depending on whether data was acknowledged.
• If the acknowledgement advances SND.UNA, continue
transmitting new data following the congestion avoidance
algorithm.
• If the acknowledgement is a duplicate ACK, set congestion
window to three segments, continue with the slow start
algorithm retransmitting unacknowledged segments.
36. Heuristic PacketHeuristic Packet
Scheduling AlgorithmScheduling Algorithm
• Send (Current + |delay1 − delay2| + 1) packet number
with maximum transmission unit bytes on the slower link
first.
• Send (|delay1−delay2|+1) number of packets each with
(maximum transmission unit)/ (|delay1−delay2|+1)bytes
on the faster link.
• Send Cumulative Acknowledge on the faster link.
• Buffer on the receiver side save packets received.
• In case of loss of packet send the packet on slower or
faster link as the size of the packet and it is rearranged
on the receiver side.
37. ConclusionConclusion
• We described the architecture and implementation of the
multipath transmission control protocol (MPTCP) in ns-
3.6, with various congestion control algorithms and
packet reordering algorithms.
• We also presented the throughput and round trip time for
various topologies using different congestion control and
packet reordering algorithms.
• We found out that congestion control algorithm given by
IETF namely, RTT Compensator and packer reordering
technique F-RTO gives good results but not the best
results.
