The document discusses network models and the layered approach to network communication. It describes how the layered approach divides the complex problem of communication into manageable layers. Each layer can be developed independently and changes can be made without affecting other layers. The document then focuses on the OSI model, which defines seven layers of network communication, from the physical layer dealing with raw transmission to the application layer supporting application processes. It provides details on the functions and responsibilities of each layer.
Network protocol lectures
Engineering + education purpose
This series of lectures was prepared for the fourth class of computer networks department In AL-Bani University College / Baghdad / Iraq.
I depend in make these lectures on-
1. Data_Communications_and_networking_3e_Forouzan
2. Internet
This series of lectures is not finished yet; I will complete it and update the PDF as soon as possible.
Forgive me for any wrong by mistake.
My regards
Marwa Moutaz/ M.Sc. studies of Communication Engineering / University of Technology/ Bagdad / Iraq
Network protocol lectures
Engineering + education purpose
This series of lectures was prepared for the fourth class of computer networks department In AL-Bani University College / Baghdad / Iraq.
I depend in make these lectures on-
1. Data_Communications_and_networking_3e_Forouzan
2. Internet
This series of lectures is not finished yet; I will complete it and update the PDF as soon as possible.
Forgive me for any wrong by mistake.
My regards
Marwa Moutaz/ M.Sc. studies of Communication Engineering / University of Technology/ Bagdad / Iraq
The OSI Model (Open Systems Interconnection Model) is a conceptual framework used to describe the functions of a networking system. The OSI model characterizes computing functions into a universal set of rules and requirements in order to support interoperability between different products and software. In the OSI reference model, the communications between a computing system are split into seven different abstraction layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.
TCP/IP Model helps you to determine how a specific computer should be connected to the internet and how data should be transmitted between them. It helps you to create a virtual network when multiple computer networks are connected together. The purpose of the TCP/IP model is to allow communication over large distances.
A
PROJECT REPORT
On
CISCO CERTIFIED NETWORK ASSOCIATE
A computer network, or simply a network, is a collection of computer and other hardware components interconnected by communication channels that allow sharing of resources and information. Where at least one process in one device is able to send/receive data to/from at least one process residing in a remote device, then the two devices are said to be in a network. Simply, more than one computer interconnected through a communication medium for information interchange is called a computer network.
The Open Systems Interconnection model (OSI model) is a conceptual model that characterizes and standardizes the communication functions of a telecommunication or computing system without regard to its underlying internal structure and technology.
The OSI Model (Open Systems Interconnection Model) is a conceptual framework used to describe the functions of a networking system. The OSI model characterizes computing functions into a universal set of rules and requirements in order to support interoperability between different products and software. In the OSI reference model, the communications between a computing system are split into seven different abstraction layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.
TCP/IP Model helps you to determine how a specific computer should be connected to the internet and how data should be transmitted between them. It helps you to create a virtual network when multiple computer networks are connected together. The purpose of the TCP/IP model is to allow communication over large distances.
A
PROJECT REPORT
On
CISCO CERTIFIED NETWORK ASSOCIATE
A computer network, or simply a network, is a collection of computer and other hardware components interconnected by communication channels that allow sharing of resources and information. Where at least one process in one device is able to send/receive data to/from at least one process residing in a remote device, then the two devices are said to be in a network. Simply, more than one computer interconnected through a communication medium for information interchange is called a computer network.
The Open Systems Interconnection model (OSI model) is a conceptual model that characterizes and standardizes the communication functions of a telecommunication or computing system without regard to its underlying internal structure and technology.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
JMeter webinar - integration with InfluxDB and Grafana
Network Models.pptx
1. Bayero University , Kano CSC7307 Computer Communication & Networks
Computer Communication and Networks
(CSC7303)
DEPARTMENT OF COMPUTER SCIENCE,
Bayero University, Kano.
1
A. A. Datti
Lecture 2: Network Models
2. Bayero University , Kano CSC7307 Computer Communication & Networks
Network Models
For successful communication , two systems must follow a common set of
rules for generating and interpreting messages
The set of rules to be followed is very complex
Layered approach provides a viable approach to deal with a complex problem
The communication functions are partitioned into a hierarchical set of layers
2
3. Bayero University , Kano CSC7307 Computer Communication & Networks
Why Layered Approach ?
A complex problem is divided into a number of
pieces of manageable and comprehensible size.
It provides structured modular approach
Each module can be developed and tested
independently
Allows easy enhancement and implementation of
the functions of a particular layer without affecting
layers 3
4. Bayero University , Kano CSC7307 Computer Communication & Networks
Why Layered Approach ?
A protocol is required when two entities need to
communicate.
When communication is not simple, we may divide
the complex task of communication into several
layers.
In this case, we may need several protocols, one for
each layer.
4
6. Bayero University , Kano CSC7307 Computer Communication & Networks
Some Basic Principles Followed In Layering
Use optimum number of layers
Put Similar function at the same layer
Create layer where there is need for different
abstraction
Allow changes of function to be made within a layer
without affecting others
Create layer boundaries for each layer with its upper
and lower layers
6
7. Bayero University , Kano CSC7307 Computer Communication & Networks
Using Layers to Describe Data Communication
8. Bayero University , Kano CSC7307 Computer Communication & Networks
ISO’s Open System Interconnection
Architecture
The most popular layered architecture that dominated data
communication and networking before 1990 was the
International Standards Organization’s (ISO’s) open
system interconnection architecture known as OSI
reference model.
Everyone believed that the OSI model would become the ultimate
standard for data communications—but this did not happened.
The TCP/IP protocol suite became the dominant architecture
because it was used and tested extensively in the Internet; the OSI
model was never fully implemented.
8
9. Bayero University , Kano CSC7307 Computer Communication & Networks
THE OSI MODEL
Established in 1947, the International Standards Organization
(ISO) is a multi- national body dedicated to worldwide
agreement on international standards.
An ISO standard that covers all aspects of network
communications is the Open Systems Interconnection (OSI)
model.
It was first introduced in the late 1970s.
9
10. Bayero University , Kano CSC7307 Computer Communication & Networks
ISO is the organization; OSI is the
model.
10
11. Bayero University , Kano CSC7307 Computer Communication & Networks
OSI Model Cont.
An open system is a set of protocols that allows any two
different systems to communicate regardless of their
underlying architecture.
The purpose of the OSI model is to show how to facilitate
communication between different systems without requiring
changes to the logic of the underlying hardware and
software.
The OSI model is not a protocol; it is a model for
understanding and designing a network architecture that is
flexible, robust, and interoperable.
11
12. Bayero University , Kano CSC7307 Computer Communication & Networks
OSI Model Cont.
The OSI model is a layered framework for the
design of network systems that allows
communication between all types of computer
systems.
It consists of seven separate but related layers,
each of which defines a part of the process of
moving information across a network.
Understanding the fundamentals of the OSI model
provides a solid basis for exploring data 12
13. Bayero University , Kano CSC7307 Computer Communication & Networks
The OSI Model
13
14. Bayero University , Kano CSC7307 Computer Communication & Networks
Layers in the OSI Model
14
15. Bayero University , Kano CSC7307 Computer Communication & Networks
Summary of OSI layer
15
17. Bayero University , Kano CSC7307 Computer Communication & Networks
OSI Layers
18. Bayero University , Kano CSC7307 Computer Communication & Networks
Physical Layer 1/3
Line configuration. The physical layer is concerned
with the connection of devices to the media. It can be
either point-to-point configuration or multipoint
configuration (a link is shared between several
devices).
Physical topology. The physical topology defines how
devices are connected to make a network. Devices can
be connected using a mesh topology (every device
connected to every other device), a star topology
(devices are connected through a central device), a
ring topology (each device is connected to the next,
forming a ring), or a bus topology (every device on a
common link). 18
19. Bayero University , Kano CSC7307 Computer Communication & Networks
Physical Layer 2/3
Concerned with transmission of raw bits over a communication
channel
Data rate . The transmission rate- number of bits sent each
second
Syncronization of bits . The sender and receiver must not only
use the same bit rate but must also be synchronized at the bit
level. In other words, the sender and the receiver clocks must be
synchronized.
19
20. Bayero University , Kano CSC7307 Computer Communication & Networks
Physical Layer 3/3
Transmission mode. The physical layer also defines
the direction of transmission between two devices:
simplex, half-duplex, or full-duplex. In the simplex
mode, only one device can send; the other can only
receive. The simplex mode is a one- way
communication. In the half-duplex mode, two
devices can send and receive, but not at the same
time. In a full-duplex (or simply duplex) mode, two
devices can send and receive at the same time.
Deal with Physical Transmission media. It can be
guided or unguided media.
20
21. Bayero University , Kano CSC7307 Computer Communication & Networks
Physical Layer
21
22. Bayero University , Kano CSC7307 Computer Communication & Networks
OSI Layers
•Provides connectivity and path selection between
two host
•Provides Logical address
•No error correction, best effort delivery.
23. Bayero University , Kano CSC7307 Computer Communication & Networks
Hop-to-Hop Delivery
23
24. Bayero University , Kano CSC7307 Computer Communication & Networks
Data Link Layer 1/3
The data link layer transforms the physical layer, a
raw transmission facility, to a reliable link.
It makes the physical layer appear error-free to the
upper layer (network layer). Other responsibilities of
the data link layer include the following:
Framing. The data link layer divides the stream of
bits received from the network layer into
manageable data units called frames.
24
25. Bayero University , Kano CSC7307 Computer Communication & Networks
Data Link Layer 2/3
Physical addressing. If frames are to be distributed
to different systems on the network, the data link
layer adds a header to the frame to define the
sender and/or receiver of the frame.
Flow control. If the rate at which the data is
absorbed by the receiver is less than the rate
produced at the sender, the data link layer imposes
a flow control mechanism to prevent overwhelming
the receiver.
25
26. Bayero University , Kano CSC7307 Computer Communication & Networks
Data Link Layer 3/3
Error control. The data link layer adds reliability to
the physical layer by adding mechanisms to detect
and retransmit damaged or lost frames. It also uses
a mechanism to recognize duplicate frames
Access control. When two or more devices are
connected to the same link, data link layer protocols
are necessary to determine which device has
control over the link at any given time.
26
27. Bayero University , Kano CSC7307 Computer Communication & Networks
Data Link Layer
27
28. Bayero University , Kano CSC7307 Computer Communication & Networks
OSI Layers
30. Bayero University , Kano CSC7307 Computer Communication & Networks
Network Layer
The network layer is responsible for the source-to-destination delivery of a
packet, between networks (links).
Whereas the data link layer oversees the delivery of the packet between
two systems on the same network (link), the network layer ensures that
each packet gets from its point of origin to its final destination.
If two systems are connected to the same link, there is usually no need for a
network layer.
However, if the two systems are attached to different networks (links) with
connecting devices between the networks (links), there is often a need for
the network layer to accomplish source-to-destination delivery.
30
31. Bayero University , Kano CSC7307 Computer Communication & Networks
Network Layer
31
32. Bayero University , Kano CSC7307 Computer Communication & Networks
Functions of Network Layer
Logical addressing. The physical addressing
implemented by the data link layer handles the
addressing problem locally. If a packet passes the
network boundary, we need another addressing system
to help distinguish the source and destination systems.
This address is called IP address
Routing. When independent networks or links are
connected together to create internetworks (network of
networks) or a large network, the connecting devices
(called routers or switches) route or switch the packets
to their final destination. One of the functions of the
network layer is to provide this mechanism
32
33. Bayero University , Kano CSC7307 Computer Communication & Networks
OSI Layers
34. Bayero University , Kano CSC7307 Computer Communication & Networks
Transport Layer
Responsible for True end-to-end Communication. Whereas, network layer
oversees source-to-destination delivery of individual packets.
34
35. Bayero University , Kano CSC7307 Computer Communication & Networks
Transport Layer
35
36. Bayero University , Kano CSC7307 Computer Communication & Networks
Function of Transport Layer
Error control. Like the data link layer, the transport
layer is responsible for error control. However, error
control at this layer is performed process-to-process
rather than across a single link.
Flow control. Like the data link layer, the transport
layer is responsible for flow control. However, flow
control at this layer is performed end to end rather
than across a single link.
36
37. Bayero University , Kano CSC7307 Computer Communication & Networks
Function of Transport Layer
Connection control. The transport layer can be
either connectionless or connection- oriented .
Segmentation and reassembly. A message is
divided into transmittable segments, with each
segment containing a sequence number. These
numbers enable the transport layer to reassemble
the message correctly upon arriving at the
destination and to identify and replace packets that
were lost in transmission.
37
38. Bayero University , Kano CSC7307 Computer Communication & Networks
Function of Transport Layer
Port Addressing : Computers often run several
programs at the same time. For this reason, source-
to-destination delivery means delivery not only from
one computer to the next but also from a specific
process (running program) on one computer to a
specific process (running program) on the other.
38
39. Bayero University , Kano CSC7307 Computer Communication & Networks
OSI Layers
40. Bayero University , Kano CSC7307 Computer Communication & Networks
Session Layer
Establishes connection and termination : The
session layer establishes connection and when the
data transfer is complete it does the termination.
Perform dialing management
◦ Who speaks , when , how long
◦ Simplex
◦ Half-duplex
◦ Full-duplex
40
41. Bayero University , Kano CSC7307 Computer Communication & Networks
Session Layer
Recovery using check-point(synchronization):
The session layer allows a process to add
checkpoints (synchronization points) into a stream
of data.
◦ For example, if a system is sending a file of 2,000 pages,
it is advisable to insert checkpoints after every 100 pages
to ensure that each 100-page unit is received and
acknowledged independently. In this case, if a crash
happens during the transmission of page 523, the only
pages that need to be resent after system recovery are
pages 501 to 523
41
42. Bayero University , Kano CSC7307 Computer Communication & Networks
OSI Layers
43. Bayero University , Kano CSC7307 Computer Communication & Networks
Presentation Layer
Translation : Because different computers use different encoding
systems (e.g. ASCII , UTF ) , the presentation layer is responsible
for interoperability between these different encoding methods. The
presentation layer at the sender changes the information from its
sender-dependent format into a common format. The presentation
layer at the receiving machine changes the common format into its
receiver-dependent format.
Data compression and Decompression : Data compression
reduces the number of bits contained in the information. Data
compression becomes particularly important in the transmission of
multimedia such as text, audio, and video.
43
44. Bayero University , Kano CSC7307 Computer Communication & Networks
Presentation Layer
Encryption and Decryption: Sometimes for
secured communication encryption and decryption
has to be done and this is the function of this
presentation layer.
44
45. Bayero University , Kano CSC7307 Computer Communication & Networks
OSI Layers
46. Bayero University , Kano CSC7307 Computer Communication & Networks
Application Layer
The application layer concern with user application
Specific application provided include
File Transfer
Email
File Management
46
47. Bayero University , Kano CSC7307 Computer Communication & Networks
Summary of OSI layer
47
48. Bayero University , Kano CSC7307 Computer Communication & Networks
Encapsulation
Data
Segments
Packet
Frame
Bits
Data
Data
49. Bayero University , Kano CSC7307 Computer Communication & Networks
Lecture 1 Continued... TCP/IP Protocol Suite
The designers of OSI assumed that this model and the protocols
developed within this model would come to dominate computer
communications and replace the rival models such as TCP/IP .
This has not happened and instead, the TCP/IP architecture has
dominated.
The TCP/IP protocol suite was developed prior to the OSI model and it is
a four layer model
Perhaps the most important reason why domination occur is that the
key TCP/IP protocols were mature and well tested at a time when similar
OSI protocols were in the development stage .
Another reason is that the OSI model is unnecessarily complex, with
seven layers to accomplish what TCP/IP does with fewer layers.
49
50. Bayero University , Kano CSC7307 Computer Communication & Networks
The TCP/IP Model
The Department of Defense (DoD) developed the
TCP/IP reference model to provide a communication
network that could continue to function in wartime.
•ARPANET (Advanced Research Projects
Agency Network) was a research network
sponsored by the DoD (U.S. Department
of Defense), 21/11/1969 UCLA-Stanford.
•It became TCP / IP (Transmission Control
Protocol / Internet Protocol) Reference
Model in 1974.
51. Bayero University , Kano CSC7307 Computer Communication & Networks
TCP/IP Applications
52. Bayero University , Kano CSC7307 Computer Communication & Networks
Transport Layer Protocols
53. Bayero University , Kano CSC7307 Computer Communication & Networks
Transport Layer Protocols
TCP is responsible for:
• end-to-end communication
• flow control
• reliability of data delivery
TCP supports a logical connection between the sending and receiving hosts
54. Bayero University , Kano CSC7307 Computer Communication & Networks
Internet Layer Protocols
The IP Protocol is
responsible for:
• defining packet format
and addressing scheme
• routing packets to remote
hosts
• transferring data between
the internet layer and the
network access layer
55. Bayero University , Kano CSC7307 Computer Communication & Networks
Internet Layer Protocols
IP - connectionless, best-effort delivery routing of
packets.
ICMP - control and messaging capabilities.
ARP - determines the data link layer address for known
IP addresses.
RARP - determines the IP address for a known MAC
address.
56. Bayero University , Kano CSC7307 Computer Communication & Networks
Internet Path Determination
57. Bayero University , Kano CSC7307 Computer Communication & Networks
Network Access Protocols
Main service : transfer data on physical
medium
• Encapsulation of IP packets into frames
• Interface to the physical medium