As computing technology evolved and the concept of linking multiple computers together into a “network” that could share data came into being, it was clear that a model was needed to define and enable those connections. Enter the OSI model in computer network idea.
This model allows various devices and software to “communicate” with one another by creating a set of universal rules and functions. Let’s dig into what the model entails.
History of the OSI Model
In the late 1970s, the continued development of computerized technology saw many companies start to introduce their own systems. These systems stood alone from others. For example, a computer at Retailer A has no way to communicate with a computer at Retailer B, with neither computer being able to communicate with the various vendors and other organizations within the retail supply chain.
Clearly, some way of connecting these standalone systems was needed, leading to researchers from France, the U.S., and the U.K. splitting into two groups – The International Organization for Standardization and the International Telegraph and Telephone Consultive Committee.
In 1983, these two groups merged their work to create “The Basic Reference Model for Open Systems Interconnection (OSI).” This model established industry standards for communication between networked devices, though the path to OSI’s implementation wasn’t as clear as it could have been. The 1980s and 1990s saw the introduction of another model – The TCP IP model – which competed against the OSI model for supremacy. TCP/IP gained so much traction that it became the cornerstone model for the then-budding internet, leading to the OSI model in computer network applications falling out of favor in many sectors. Despite this, the OSI model is still a valuable reference point for students who want to learn more about networking and still have some practical uses in industry.
The OSI Reference Model
The OSI model works by splitting the concept of computers communicating with one another into seven computer network layers (defined below), each offering standardized rules for its specific function. During the rise of the OSI model, these layers worked in concert, allowing systems to communicate as long as they followed the rules.
Though the OSI model in computer network applications has fallen out of favor on a practical level, it still offers several benefits:
- The OSI model is perfect for teaching network architecture because it defines how computers communicate.
- OSI is a layered model, with separation between each layer, so one layer doesn’t affect the operation of any other.
- The OSI model offers flexibility because of the distinctions it makes between layers, with users being able to replace protocols in any layer without worrying about how they’ll impact the other layers.
The 7 Layers of the OSI Model
The OSI reference model in computer network teaching is a lot like an onion. It has several layers, each standing alone but each needing to be peeled back to get a result. But where peeling back the layers of an onion gets you a tasty ingredient or treat, peeling them back in the OSI model delivers a better understanding of networking and the protocols that lie behind it.
Each of these seven layers serves a different function.
Layer 1: Physical Layer
Sitting at the lowest level of the OSI model, the physical layer is all about the hows and wherefores of transmitting electrical signals from one device to another. Think of it as the protocols needed for the pins, cables, voltages, and every other component of a physical device if said device wants to communicate with another that uses the OSI model.
Layer 2: Data Link Layer
With the physical layer in place, the challenge shifts to transmitting data between devices. The data layer defines how node-to-node transfer occurs, allowing for the packaging of data into “frames” and the correction of errors that may happen in the physical layer.
The data layer has two “sub-layers” of its own:
- MAC – Media Access Controls that offer multiplexing and flow control to govern a device’s transmissions over an OSI network.
- LLC – Logical Link Controls that offer error control over the physical media (i.e., the devices) used to transmit data across a connection.
Layer 3: Network Layer
The network layer is like an intermediary between devices, as it accepts “frames” from the data layer and sends them on their way to their intended destination. Think of this layer as the postal service of the OSI model in computer network applications.
Layer 4: Transport Layer
If the network layer is a delivery person, the transport layer is the van that the delivery person uses to carry their parcels (i.e., data packets) between addresses. This layer regulates the sequencing, sizing, and transferring of data between hosts and systems. TCP (Transmission Control Protocol) is a good example of a transport layer in practical applications.
Layer 5: Session Layer
When one device wants to communicate with another, it sets up a “session” in which the communication takes place, similar to how your boss may schedule a meeting with you when they want to talk. The session layer regulates how the connections between machines are set up and managed, in addition to providing authorization controls to ensure no unwanted devices can interrupt or “listen in” on the session.
Layer 6: Presentation Layer
Presentation matters when sending data from one system to another. The presentation layer “pretties up” data by formatting and translating it into a syntax that the recipient’s application accepts. Encryption and decryption is a perfect example, as a data packet can be encrypted to be unreadable to anybody who intercepts it, only to be decrypted via the presentation layer so the intended recipient can see what the data packet contains.
Layer 7: Application Layer
The application layer is a front end through which the end user can interact with everything that’s going on behind the scenes in the network. It’s usually a piece of software that puts a user-friendly face on a network. For instance, the Google Chrome web browser is an application layer for the entire network of connections that make up the internet.
Interactions Between OSI Layers
Though each of the OSI layers in computer networks is independent (lending to the flexibility mentioned earlier), they must also interact with one another to make the network functional.
We see this most obviously in the data encapsulation and de-encapsulation that occurs in the model. Encapsulation is the process of adding information to a data packet as it travels, with de-encapsulation being the method used to remove that data added data so the end user can read what was originally sent. The previously mentioned encryption and decryption of data is a good example.
That process of encapsulation and de-encapsulation defines how the OSI model works. Each layer adds its own little “flavor” to the transmitted data packet, with each subsequent layer either adding something new or de-encapsulating something previously added so it can read the data. Each of these additions and subtractions is governed by the protocols set within each layer. A perfect network can only exist if these protocols properly govern data transmission, allowing for communication between each layer.
Real-World Applications of the OSI Model
There’s a reason why the OSI model in computer network study is often called a “reference” model – though important, it was quickly replaced with other models. As a result, you’ll rarely see the OSI model used as a way to connect devices, with TCP/IP being far more popular. Still, there are several practical applications for the OSI model.
Network Troubleshooting and Diagnostics
Given that some modern computer networks are unfathomably complex, picking out a single error that messes up the whole communication process can feel like navigating a minefield. Every wrong step causes something else to blow up, leading to more problems than you solve. The OSI model’s layered approach offers a way to break down the different aspects of a network to make it easier to identify problems.
Network Design and Implementation
Though the OSI model has few practical purposes, as a theoretical model it’s often seen as the basis for all networking concepts that came after. That makes it an ideal teaching tool for showcasing how networks are designed and implemented. Some even refer to the model when creating networks using other models, with the layered approach helping understand complex networks.
Enhancing Network Security
The concept of encapsulation and de-encapsulation comes to the fore again here (remember – encryption), as this concept shows us that it’s dangerous to allow a data packet to move through a network with no interactions. The OSI model shows how altering that packet as it goes on its journey makes it easier to protect data from unwanted eyes.
Limitations and Criticisms of the OSI Model
Despite its many uses as a teaching tool, the OSI model in computer network has limitations that are the reasons why it sees few practical applications:
- Complexity – As valuable as the layered approach may be to teaching networks, it’s often too complex to execute in practice.
- Overlap – The very flexibility that makes OSI great for people who want more control over their networks can come back to bite the model. The failure to implement proper controls and protocols can lead to overlap, as can the layered approach itself. Each of the computer network layers needs the others to work.
- The Existence of Alternatives – The OSI model walked so other models could run, establishing many fundamental networking concepts that other models executed better in practical terms. Again, the massive network known as the internet is a great example, as it uses the TCP/IP model to reduce complexity and more effectively transmit data.
Use the OSI Reference Model in Computer Network Applications
Though it has little practical application in today’s world, the OSI model in computer network terms is a theoretical model that played a crucial role in establishing many of the “rules” of networking still used today. Its importance is still recognized by the fact that many computing courses use the OSI model to teach the fundamentals of networks.
Think of learning about the OSI model as being similar to laying the foundations for a house. You’ll get to grips with the basic concepts of how networks work, allowing you to build up your knowledge by incorporating both current networking technology and future advancements to become a networking specialist.
-
From the same author
Read the articleAs computing technology evolved and the concept of linking multiple computers together into a “network” that could share data came into being, it was clear that a model was needed to define and enable those connections. Enter the OSI model in computer network idea.
This model allows various devices and software to “communicate” with one another by creating a set of universal rules and functions. Let’s dig into what the model entails.
History of the OSI Model
In the late 1970s, the continued development of computerized technology saw many companies start to introduce their own systems. These systems stood alone from others. For example, a computer at Retailer A has no way to communicate with a computer at Retailer B, with neither computer being able to communicate with the various vendors and other organizations within the retail supply chain.
Clearly, some way of connecting these standalone systems was needed, leading to researchers from France, the U.S., and the U.K. splitting into two groups – The International Organization for Standardization and the International Telegraph and Telephone Consultive Committee.
In 1983, these two groups merged their work to create “The Basic Reference Model for Open Systems Interconnection (OSI).” This model established industry standards for communication between networked devices, though the path to OSI’s implementation wasn’t as clear as it could have been. The 1980s and 1990s saw the introduction of another model – The TCP IP model – which competed against the OSI model for supremacy. TCP/IP gained so much traction that it became the cornerstone model for the then-budding internet, leading to the OSI model in computer network applications falling out of favor in many sectors. Despite this, the OSI model is still a valuable reference point for students who want to learn more about networking and still have some practical uses in industry.
The OSI Reference Model
The OSI model works by splitting the concept of computers communicating with one another into seven computer network layers (defined below), each offering standardized rules for its specific function. During the rise of the OSI model, these layers worked in concert, allowing systems to communicate as long as they followed the rules.
Though the OSI model in computer network applications has fallen out of favor on a practical level, it still offers several benefits:
- The OSI model is perfect for teaching network architecture because it defines how computers communicate.
- OSI is a layered model, with separation between each layer, so one layer doesn’t affect the operation of any other.
- The OSI model offers flexibility because of the distinctions it makes between layers, with users being able to replace protocols in any layer without worrying about how they’ll impact the other layers.
The 7 Layers of the OSI Model
The OSI reference model in computer network teaching is a lot like an onion. It has several layers, each standing alone but each needing to be peeled back to get a result. But where peeling back the layers of an onion gets you a tasty ingredient or treat, peeling them back in the OSI model delivers a better understanding of networking and the protocols that lie behind it.
Each of these seven layers serves a different function.
Layer 1: Physical Layer
Sitting at the lowest level of the OSI model, the physical layer is all about the hows and wherefores of transmitting electrical signals from one device to another. Think of it as the protocols needed for the pins, cables, voltages, and every other component of a physical device if said device wants to communicate with another that uses the OSI model.
Layer 2: Data Link Layer
With the physical layer in place, the challenge shifts to transmitting data between devices. The data layer defines how node-to-node transfer occurs, allowing for the packaging of data into “frames” and the correction of errors that may happen in the physical layer.
The data layer has two “sub-layers” of its own:
- MAC – Media Access Controls that offer multiplexing and flow control to govern a device’s transmissions over an OSI network.
- LLC – Logical Link Controls that offer error control over the physical media (i.e., the devices) used to transmit data across a connection.
Layer 3: Network Layer
The network layer is like an intermediary between devices, as it accepts “frames” from the data layer and sends them on their way to their intended destination. Think of this layer as the postal service of the OSI model in computer network applications.
Layer 4: Transport Layer
If the network layer is a delivery person, the transport layer is the van that the delivery person uses to carry their parcels (i.e., data packets) between addresses. This layer regulates the sequencing, sizing, and transferring of data between hosts and systems. TCP (Transmission Control Protocol) is a good example of a transport layer in practical applications.
Layer 5: Session Layer
When one device wants to communicate with another, it sets up a “session” in which the communication takes place, similar to how your boss may schedule a meeting with you when they want to talk. The session layer regulates how the connections between machines are set up and managed, in addition to providing authorization controls to ensure no unwanted devices can interrupt or “listen in” on the session.
Layer 6: Presentation Layer
Presentation matters when sending data from one system to another. The presentation layer “pretties up” data by formatting and translating it into a syntax that the recipient’s application accepts. Encryption and decryption is a perfect example, as a data packet can be encrypted to be unreadable to anybody who intercepts it, only to be decrypted via the presentation layer so the intended recipient can see what the data packet contains.
Layer 7: Application Layer
The application layer is a front end through which the end user can interact with everything that’s going on behind the scenes in the network. It’s usually a piece of software that puts a user-friendly face on a network. For instance, the Google Chrome web browser is an application layer for the entire network of connections that make up the internet.
Interactions Between OSI Layers
Though each of the OSI layers in computer networks is independent (lending to the flexibility mentioned earlier), they must also interact with one another to make the network functional.
We see this most obviously in the data encapsulation and de-encapsulation that occurs in the model. Encapsulation is the process of adding information to a data packet as it travels, with de-encapsulation being the method used to remove that data added data so the end user can read what was originally sent. The previously mentioned encryption and decryption of data is a good example.
That process of encapsulation and de-encapsulation defines how the OSI model works. Each layer adds its own little “flavor” to the transmitted data packet, with each subsequent layer either adding something new or de-encapsulating something previously added so it can read the data. Each of these additions and subtractions is governed by the protocols set within each layer. A perfect network can only exist if these protocols properly govern data transmission, allowing for communication between each layer.
Real-World Applications of the OSI Model
There’s a reason why the OSI model in computer network study is often called a “reference” model – though important, it was quickly replaced with other models. As a result, you’ll rarely see the OSI model used as a way to connect devices, with TCP/IP being far more popular. Still, there are several practical applications for the OSI model.
Network Troubleshooting and Diagnostics
Given that some modern computer networks are unfathomably complex, picking out a single error that messes up the whole communication process can feel like navigating a minefield. Every wrong step causes something else to blow up, leading to more problems than you solve. The OSI model’s layered approach offers a way to break down the different aspects of a network to make it easier to identify problems.
Network Design and Implementation
Though the OSI model has few practical purposes, as a theoretical model it’s often seen as the basis for all networking concepts that came after. That makes it an ideal teaching tool for showcasing how networks are designed and implemented. Some even refer to the model when creating networks using other models, with the layered approach helping understand complex networks.
Enhancing Network Security
The concept of encapsulation and de-encapsulation comes to the fore again here (remember – encryption), as this concept shows us that it’s dangerous to allow a data packet to move through a network with no interactions. The OSI model shows how altering that packet as it goes on its journey makes it easier to protect data from unwanted eyes.
Limitations and Criticisms of the OSI Model
Despite its many uses as a teaching tool, the OSI model in computer network has limitations that are the reasons why it sees few practical applications:
- Complexity – As valuable as the layered approach may be to teaching networks, it’s often too complex to execute in practice.
- Overlap – The very flexibility that makes OSI great for people who want more control over their networks can come back to bite the model. The failure to implement proper controls and protocols can lead to overlap, as can the layered approach itself. Each of the computer network layers needs the others to work.
- The Existence of Alternatives – The OSI model walked so other models could run, establishing many fundamental networking concepts that other models executed better in practical terms. Again, the massive network known as the internet is a great example, as it uses the TCP/IP model to reduce complexity and more effectively transmit data.
Use the OSI Reference Model in Computer Network Applications
Though it has little practical application in today’s world, the OSI model in computer network terms is a theoretical model that played a crucial role in establishing many of the “rules” of networking still used today. Its importance is still recognized by the fact that many computing courses use the OSI model to teach the fundamentals of networks.
Think of learning about the OSI model as being similar to laying the foundations for a house. You’ll get to grips with the basic concepts of how networks work, allowing you to build up your knowledge by incorporating both current networking technology and future advancements to become a networking specialist.
-
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The Open Institute of Technology (OPIT) is the perfect place for those looking to master the core skills and gain the fundamental knowledge they need to enter the exciting and dynamic environment of the tech industry. While OPIT’s various degrees and courses unlock the doors to numerous careers, students may not know exactly which line of work they wish to enter, or how, exactly, to take the next steps.
That’s why, as well as providing exceptional online education in fields like Responsible AI, Computer Science, and Digital Business, OPIT also offers an array of career-related services, like the Peer Career Mentoring Program. Designed to provide the expert advice and support students need, this program helps students and alumni gain inspiration and insight to map out their future careers.
Introducing the OPIT Peer Career Mentoring Program
As the name implies, OPIT’s Peer Career Mentoring Program is about connecting students and alumni with experienced peers to provide insights, guidance, and mentorship and support their next steps on both a personal and professional level.
It provides a highly supportive and empowering space in which current and former learners can receive career-related advice and guidance, harnessing the rich and varied experiences of the OPIT community to accelerate growth and development.
Meet the Mentors
Plenty of experienced, expert mentors have already signed up to play their part in the Peer Career Mentoring Program at OPIT. They include managers, analysts, researchers, and more, all ready and eager to share the benefits of their experience and their unique perspectives on the tech industry, careers in tech, and the educational experience at OPIT.
Examples include:
- Marco Lorenzi: Having graduated from the MSc in Applied Data Science and AI program at OPIT, Marco has since progressed to a role as a Prompt Engineer at RWS Group and is passionate about supporting younger learners as they take their first steps into the workforce or seek career evolution.
- Antonio Amendolagine: Antonio graduated from the OPIT MSc in Applied Data Science and AI and currently works as a Product Marketing and CRM Manager with MER MEC SpA, focusing on international B2B businesses. Like other mentors in the program, he enjoys helping students feel more confident about achieving their future aims.
- Asya Mantovani: Asya took the MSc in Responsible AI program at OPIT before taking the next steps in her career as a Software Engineer with Accenture, one of the largest IT companies in the world, and a trusted partner of the institute. With a firm belief in knowledge-sharing and mutual support, she’s eager to help students progress and succeed.
The Value of the Peer Mentoring Program
The OPIT Peer Career Mentoring Program is an invaluable source of support, inspiration, motivation, and guidance for the many students and graduates of OPIT who feel the need for a helping hand or guiding light to help them find the way or make the right decisions moving forward. It’s a program built around the sharing of wisdom, skills, and insights, designed to empower all who take part.
Every student is different. Some have very clear, fixed, and firm objectives in mind for their futures. Others may have a slightly more vague outline of where they want to go and what they want to do. Others live more in the moment, focusing purely on the here and now, but not thinking too far ahead. All of these different types of people may need guidance and support from time to time, and peer mentoring provides that.
This program is also just one of many ways in which OPIT bridges the gaps between learners around the world, creating a whole community of students and educators, linked together by their shared passions for technology and development. So, even though you may study remotely at OPIT, you never need to feel alone or isolated from your peers.
Additional Career Services Offered by OPIT
The Peer Career Mentoring Program is just one part of the larger array of career services that students enjoy at the Open Institute of Technology.
- Career Coaching and Support: Students can schedule one-to-one sessions with the institute’s experts to receive insightful feedback, flexibly customized to their exact needs and situation. They can request resume audits, hone their interview skills, and develop action plans for the future, all with the help of experienced, expert coaches.
- Resource Hub: Maybe you need help differentiating between various career paths, or seeing where your degree might take you. Or you need a bit of assistance in handling the challenges of the job-hunting process. Either way, the OPIT Resource Hub contains the in-depth guides you need to get ahead and gain practical skills to confidently move forward.
- Career Events: Regularly, OPIT hosts online career event sessions with industry experts and leaders as guest speakers about the topics that most interest today’s tech students and graduates. You can join workshops to sharpen your skills and become a better prospect in the job market, or just listen to the lessons and insights of the pros.
- Internship Opportunities: There are few better ways to begin your professional journey than an internship at a top-tier company. OPIT unlocks the doors to numerous internship roles with trusted institute partners, as well as additional professional and project opportunities where you can get hands-on work experience at a high level.
In addition to the above, OPIT also teams up with an array of leading organizations around the world, including some of the biggest names, including AWS, Accenture, and Hype. Through this network of trust, OPIT facilitates students’ steps into the world of work.
Start Your Study Journey Today
As well as the Peer Career Mentoring Program, OPIT provides numerous other exciting advantages for those who enroll, including progressive assessments, round-the-clock support, affordable rates, and a team of international professors from top universities with real-world experience in technology. In short, it’s the perfect place to push forward and get the knowledge you need to succeed.
So, if you’re eager to become a tech leader of tomorrow, learn more about OPIT today.
The world has entered the age of artificial intelligence (AI), and this exciting new technology is already changing the face of society in an ever-growing number of ways. It’s influencing a plethora of industries and sectors, from healthcare and education to finance and urban planning. This guide explores AI’s impact on three of the core pillars of life: business, education, and sustainability.
AI in Business: Unlocking Unprecedented Opportunities
In the world of business, the number of uses of AI is growing by the day. Whether it’s in sales, marketing, customer relations, operational optimization, cybersecurity, data management, or some other aspect of organizational life, there are so many ways this technology can unlock new opportunities or expedite existing processes.
Take data as an example. Many businesses now collect and use large amounts of data to inform their decisions in areas like product development or marketing strategy. But they have, up to now, been limited in how they can structure, visualize, and analyze their data. AI changes all that, as it can dig into vast databases with ease, extracting insights to drive actionable decisions in no time.
AI also bridges gaps in communications. It has the power to speak in most major languages, translating audio or written text with astonishing accuracy in an instant. In a globalized world, where many businesses buy and sell with partners, suppliers, investors, and other stakeholders from other nations, AI can help them communicate and exchange information more easily and reliably.
AI in Education: Democratizing and Accelerating the Learning Process
In the educational sector, AI is solving problems that have plagued this industry for generations and transforming the ways in which students learn and teachers teach. It can be used, for example, to personalize a student’s learning plan or adapt content to align with each learner’s favored learning style, making it easier for them to soak up and retain information and skills.
AI’s generative capabilities are also proving useful in the education sector. Teachers, for example, can turn to generative AI models to create lesson plans or supplementary content to support their courses, such as tables, charts, infographics, and images. This all helps to make the learning experience more diverse, dynamic, and engaging for every kind of learner.
On a broader level, there’s clear potential for AI to democratize education across the globe, making learning more accessible to all. That includes those in developing nations who may normally lack opportunities to gain knowledge and skills to achieve their ambitions. If harnessed correctly and responsibly, this technology could elevate education to whole new heights.
AI in Sustainability: Smarter Cities and Next-Level Efficiency
Sustainability is one of the sticking points when talking about AI, as many critics of the technology point to the fact that it involves huge amounts of energy and relies heavily on large and costly data centers to operate. At the same time, AI could also solve many of the sustainability crises facing the world today, uncovering solutions and innovations that may have previously taken decades to develop.
It’s already proving its value in this domain. For instance, DeepMind developed an AI system that was actually able to optimize data center energy efficiency, cutting the amount of energy used to cool data center hardware by a whopping 40% and improving energy efficiency in certain centers by 15%. That’s just one example, and it’s only the start of what AI could do from an environmental perspective.
This tech is also making cities smarter, more efficient, and more pleasant in which to live through AI-powered navigation aids or traffic redistribution systems. It also holds potential for future urban planning, city development, and infrastructure construction, provided the correct systems and frameworks can be established to make the best use of AI’s advantages.
The Ethical Challenges and Risks of AI
Despite its almost countless advantages and possible applications, AI is not without its flaws. This technology brings challenges and risks to go along with its opportunities, and five leading examples include:
- Bias: Algorithmic bias is an issue that has already presented itself during the relatively brief existence of AI so far. Some systems, for example, have issued responses or generated content that could be classified as discriminatory or prejudiced, due to the training data they were given.
- Privacy: There are fears among populations and analysts about the amount of data being fed into AI systems and how such data could be misused, potentially violating people’s rights of privacy and falling foul of data privacy regulations, such as GDPR.
- Misuse: Like so many game-changing technologies, AI has the potential to be used for both benevolent and malicious purposes. It may be used to spread misinformation and “fake news,” influence public opinion, or even in cyber-attacks, for instance.
- Over-reliance: AI is so powerful, with the capacity to carry out tasks with remarkable precision and speed, that it will be tempting for organizations to integrate it into many of their workflows and decision-making processes. But AI cannot be treated as a substitute for human judgment.
- Sustainability: There are also fears about the energy costs associated with AI and the data centers needed to power it, plus the fact that some elements of the burgeoning AI industry may exploit workers in poorer nations worldwide.
Solving These Challenges: Regulation and Responsible Use of AI
With the right approach, it is possible to solve all the above challenges, and more, making AI the most valuable and beneficial new technology the world has seen since the advent of the internet. This will require a two-pronged strategy focusing on both regulation and responsible usage.
Europe is already leading the way in the first aspect. It has introduced the AI Act – a world-first regulatory framework related to artificial intelligence, laying out how it should be used to drive innovation without infringing on the fundamental rights of workers and the larger public.
Educational institutions like the OPIT – Open Institute of Technology are also leading the way in the second aspect, educating people around the world on how to work with AI in a responsible, ethical way, through programs like the MSc in Responsible Artificial Intelligence.
By establishing rules and regulations about AI’s usage and educating the tech leaders of tomorrow in how to work with AI in a fair and responsible way, the future is bright for this exciting and extraordinary new technology.
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