The document discusses congestion control in computer networks, detailing techniques to regulate traffic and prevent overload, such as TCP congestion control, traffic shaping, and resource reservation. It outlines general principles for efficient network resource use including fairness, efficiency, and stability, and describes methods like choke packets and jitter control to manage congestion and packet delays. Additionally, the document covers crucial protocols like IP, BGP, and OSPF that facilitate data routing and communication on networks.

1. DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING [CYBER SECURITY]
SECOND YEAR 4th SEM
Subject: Computer Networks
Topic: Congestion Control
Guided By: Dr. Pravin Kullurkar Sir

3. Congestion Control Algorithm
 Congestion control is a technique used to regulate network traffic and prevent network
congestion.
 It works by monitoring network conditions and adjusting the amount of data being sent to
avoid overloading the network.
 The most common congestion control
algorithms are:
• TCP Congestion Control
• Leaky Bucket
• Random Early Detection
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4. General Principles Of Congestion Control
The general principles of congestion control aim to ensure that network resources are used
efficiently and that network traffic is regulated to prevent congestion.
The following are some of the general principles of congestion control:
• Fairness: All users of the network should have equal access to network resources
and the congestion control algorithm should ensure that no single user consumes
more than their fair share.
• Efficiency: The congestion control algorithm should allow for efficient use of network
resources, avoiding both underutilization and overutilization.
• Stability: The congestion control algorithm should maintain stability in the network,
preventing rapid fluctuations in network conditions that can lead to congestion.
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5. General Principles Prevention Policies
Prevention policies aim to prevent network congestion before it occurs. These policies
typically focus on controlling the rate at which data is sent and regulating the amount of
network traffic.
Some common prevention policies include:
• Traffic Shaping: Traffic shaping regulates the amount of data sent over the network
by controlling the rate at which data is transmitted.
• Quality of Service (QoS): QoS policies prioritize different types of network traffic
based on their importance, ensuring that critical traffic is transmitted first.
• Resource Reservation: Resource reservation policies reserve network resources for
specific applications or users, ensuring that these applications or users have the
resources they need when they need them.
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6. Traffic Shaping
Traffic shaping is a network management technique used to control the amount of data that
is sent over a network.
It works by regulating the rate at which data is transmitted, ensuring that the network is not
overloaded and preventing congestion.
Traffic shaping can be implemented in several ways, including:
• Queue Management: Traffic shaping can be implemented at the network edge by
managing the data that is placed in the transmission queue. Packets can be
dropped, delayed, or prioritized based on their importance.
• Rate Limiting: Traffic shaping can be implemented by limiting the rate at which data
is transmitted. This ensures that the network is not flooded with data, preventing
congestion.
• Packet Prioritization: Traffic shaping can also be implemented by prioritizing different
types of network traffic based on their importance.
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7. Traffic Shaping
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8. Flow Specification
Flow specification is a technique used to describe and control the characteristics of
network traffic flows.
A flow is a sequence of packets that are sent between a specific source and destination
and that share common characteristics such as source and destination IP addresses,
source and destination port numbers, and protocol type.
Flow specification is used to define the parameters that describe the desired behavior of a
flow, including:
• Bandwidth: The amount of bandwidth that should be reserved for the flow.
• Latency: The maximum acceptable delay for packets in the flow.
• Jitter: The maximum acceptable variation in packet delay for packets in the flow.
• Loss: The maximum acceptable loss rate for packets in the flow.
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9. Choke Packet
Choke packets are packets that are intentionally discarded by network devices in order to
control network congestion.
They are used in congestion control algorithms to regulate the flow of data in a network.
When a network becomes congested, the amount of data being transmitted can exceed
the capacity of the network, causing delays and lost packets.
 Choke packets are used to temporarily restrict the flow of data and reduce the amount of
data being transmitted, allowing the network to recover from the congestion.
In conclusion , choke packets are an important tool for managing network congestion and
ensuring the efficient operation of networks. They are used by congestion control
algorithms to regulate the flow of data and prevent network congestion from becoming a
problem.
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10. Choke Packet
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11. Jitter Control
Jitter control refers to the process of controlling the variability of the delay (or "jitter") in
packet-switched networks.
Jitter is the fluctuation in the delay of the packets as they travel from the source to the
destination, and it can have a significant impact on the quality of real-time applications
such as voice and video over IP.
Jitter control techniques aim to ensure that packets arrive at the destination with a
consistent and predictable delay.
This is achieved by implementing algorithms that monitor the delay of packets and make
adjustments to ensure that the delay remains within a specified range.
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12. Load Shedding
Load shedding is a technique used in computer networks and electrical power systems to
manage excessive demand on the system.
When a system is experiencing high demand, load shedding is used to temporarily remove
some of the demand, reducing the overall load on the system.
In the context of computer networks, load shedding is used to manage congestion in the
network.
When the network becomes congested, load shedding algorithms will temporarily restrict
the flow of data, discarding some packets and allowing the network to recover from the
congestion.
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13. IP Protocol
The Internet Protocol (IP) is a communication protocol used for transmitting data over
networks.
It is one of the most important protocols in the Internet Protocol suite, and is responsible
for routing data packets from one network to another.
IP operates at the network layer of the OSI model and provides the basic service of
delivering data packets from the source host to the destination host based on their IP
addresses.
 IP does not guarantee that the packets will arrive in order, or that they will not be lost or
duplicated. This responsibility is left to other protocols, such as the Transmission Control
Protocol (TCP).
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14. IP Protocol
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15. IP Address
An IP address (Internet Protocol address) is a unique numerical label assigned to each
device connected to a computer network that uses the Internet Protocol for communication.
It serves two main purposes:
• Identification: The IP address identifies the device that is sending or receiving data,
allowing other devices to communicate with it.
• Location: The IP address provides the location of the device in the network, allowing
data to be routed from the source to the destination.
There are two versions of IP addresses: IPv4 and IPv6. IPv4 addresses are 32-bit addresses
while IPv6 addresses are 128-bit.
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16. Subnet
A subnet (short for subnetwork) is a logical division of an IP network into multiple smaller
network segments.
The primary purpose of subnetting is to break down a large network into smaller, more
manageable pieces, making it easier to control network traffic and to improve network
security.
Subnetting allows an organization to use a single IP address space for multiple physical
networks, and to divide a large network into smaller, more secure segments
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17. Internet Control Protocols
The term "Internet Control Protocols" refers to a set of protocols that are used to manage
and control the operation of the Internet.
These protocols provide the underlying infrastructure for communication and data transfer
over the Internet.
Some common Internet control protocols include:
• Internet Protocol (IP): Responsible for routing and forwarding packets between
network devices.
• Transmission Control Protocol (TCP): A reliable, connection-oriented transport
protocol that provides flow control, error checking, and reliable delivery of data.
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18. • User Datagram Protocol (UDP): An unreliable, connectionless transport protocol used
for applications that do not require reliable delivery of data.
• Internet Control Message Protocol (ICMP): Used to send messages about network
conditions and provide error-reporting and control functions for the IP protocol.
• Domain Name System (DNS): A hierarchical, decentralized naming system used to
map domain names to IP addresses.
These protocols work together to provide the infrastructure for communication and data transfer
over the Internet.
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19. OSPF
Open Shortest Path First (OSPF) is a routing protocol used for Internet Protocol (IP)
networks.
It is a link-state routing (LSR) protocol, which means that it builds a complete map of the
network and uses this information to make routing decisions.
OSPF is commonly used in large enterprise networks and is known for its scalability and fast
convergence times.
One of the key benefits of OSPF is its hierarchical design, which allows for efficient and
scalable routing in large networks.
In conclusion, OSPF is a robust and widely-used routing protocol that provides efficient and
scalable routing in IP networks.
Its hierarchical design and fast convergence times make it a popular choice for large
enterprise networks.
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20. OSPF
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21. BGP
Border Gateway Protocol (BGP) is a routing protocol used for exchanging routing
information between routers in different autonomous systems (AS) on the Internet.
It is the protocol used to route traffic on the Internet and is the backbone of the Internet's
routing system.
 BGP routers exchange information about reachable IP addresses and the paths to those
addresses with other BGP routers.
BGP is used by Internet service providers (ISPs) to exchange routing information with
each other and to provide Internet connectivity to their customers.
It provides a scalable solution for routing Internet traffic and allows for the creation of
large-scale networks with multiple ISPs.
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22. BGP
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23. Thank You!
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