TCP/IP is the foundation of modern networking, but it is not a single, unified protocol. Rather, it is a family of protocols that follow different models and standards, depending on the context and the purpose. In this article, you will learn how to compare and contrast different TCP/IP models and standards, and why they matter for your network design and troubleshooting.
The TCP/IP model is the most widely used and accepted framework for describing the functions and layers of network protocols. It consists of four layers: application, transport, internet, and network access. Each layer provides a specific service to the upper layer, and uses the service of the lower layer. The TCP/IP model is not a strict standard, but rather a conceptual guide that allows different protocols to interoperate.
There are various concepts of TCP/IP depending on your use case. You can either use the full 7 layers or do a modified 5 or 4-layer approach. No matter the use case you need to have a basic understanding of what TCP/IP is.
The OSI model is another framework for describing network protocols, but it is more detailed and complex than the TCP/IP model. It consists of seven layers: application, presentation, session, transport, network, data link, and physical. The OSI model is a standard, not a protocol, and it defines the functions and interfaces of each layer. The OSI model is useful for teaching and learning network concepts, but it is not widely implemented in practice.
The OSI model gives me better and quick understanding of how the network interacts. I will recommend that people should make this particular model the bedrock of their networking knowledge.
The DoD model is an older and simpler framework for describing network protocols, developed by the US Department of Defense. It consists of three layers: process/application, host-to-host, and network. The DoD model is similar to the TCP/IP model, but it combines the application, presentation, and session layers into one layer, and it uses different names for the transport and internet layers. The DoD model is the basis for the original TCP/IP protocols.
This model is seldom taught in military networks anymore. As a service member with over 20 years in the IT field for the U.S. Navy we have adapted to newer technologies and with that, the approach we take to the IP model has evolved as well. For the Navy at least, we have each new IT understand the full OSI model no matter the network.
The Internet Protocol Suite is the collection of protocols that implement the TCP/IP model. It includes protocols such as TCP, UDP, IP, ICMP, ARP, DHCP, DNS, HTTP, FTP, SMTP, and many more. Each protocol has a specific function and format, and follows a standard that defines its rules and parameters. The Internet Protocol Suite is constantly evolving and expanding, as new protocols are developed and adopted.
Something to mention when you are looking at these various protocols is the Port they reside in. This will become especially important when it comes time to secure your network from specific traffic types.
The TCP/IP blogs and podcasts are online resources that provide information and insights on various aspects of TCP/IP networking, created and maintained by experts, enthusiasts, and practitioners who share their knowledge and experience with the network community. For instance, Packet Pushers is a podcast that covers network engineering, architecture, design, operations, and news; The Network Collective is a podcast that features network professionals who discuss topics such as routing, switching, security, automation; Network World is a blog that covers network trends, technologies, products, and best practices; IP Space is a blog that provides in-depth analysis and advice on network design, architecture, automation, and troubleshooting.
To gain a deeper understanding of TCP/IP networking and how to design, implement, and troubleshoot networks using different protocols, you need to compare and contrast different TCP/IP models and standards. To do this, consider the purpose, scope, structure, and compatibility of each model or standard. Ask yourself questions such as: what is the goal and context of each model or standard? How many layers does each have, and what are their names and functions? How do the layers of each model or standard relate to each other, and to the layers of other models or standards? What are the advantages and disadvantages of each model or standard? What are the common and unique protocols of each model or standard, and how do they work? Answering these questions can help you gain a better understanding of TCP/IP models and standards.
I would add. The TCP/IP Stack is used for contemporary networking. The OSI model is used for visualizing the different layers of the TCP/IP stack and the associated PDU's (Protocol data units) bits, frames, packets, segments, data/meta data. but is not used in configuring contemporary Network Engineering services.
I would add that each of the protocols in the suite plays a specific role. For example, BGP, the acronym for Border Gateway Protocol is, as its name suggests, a protocol that deals with issues that occur at the boundaries or edges of a specific network. This function exists to help resolve issues that would arise at those boundaries and provides a standard way to deal with interoperability issues. In fact, all protocols serve that purpose for specific interworking issues. The members of the IETF did this rather than continually upversioning IP, the strategy that had previously been used at Telcordia/Bell Labs.