Justin Ellingwood Introduction A basic understanding of networking is important for anyone managing a server. Not only is it essential for getting your services online and running smoothly, it also gives you the insight to diagnose problems.
Forget the configuration details — what are the insights?
Networking is about communication Text is the simplest way to communicate Protocols are standards for reading and writing text Beneath the details, networking is an IM conversation.
TCP relies on lower levels and can send binary data, but ignore that for now: We connect to google. We press Enter a few times and await the reply: The mighty Google is not pleased. But, we had a conversation: The Forms To Fill Out Unstructured chats are too carefree — how does the server know what we want to do?
What does it mean?
Connect to server google. Using the HTTP format, the above request looks like this: Sun, 15 Mar The bottom part is HTML for the browser to display. But why the junk up top? Well, suppose we just got the raw HTML to display.
But what about errors: Some metadata data about data is useful. When we order a book from Amazon we expect a packing slip describing the order: Here we see infamous status codes like resource not found or everything OK.
Insights From Protocols Studying existing, popular systems is a great way to understand engineering decisions. Here are a few: Binary vs Plain Text Binary data is more efficient than text, but more difficult to debug and generate how many hex editors do you know to use?
Lower-level protocols, the backbone of the internet, use binary data to maintain performance. Application-level protocols HTTP and above use text data for ease of interoperability.
Stateless Some protocols are stateful, which means the server remembers the chat with the client. With SMTP, for example, the client opens a connection and issues commands one at a time such as adding recipients to an emailand closes the connection.
Stateful communication is useful in transactions that have many steps or conditions. Stateless communication is simpler: How do we extend old protocols for new users?
How are errors handled and communicated? Can the client just retry or does the server need to reset state? HTTP comes with its own set of error codes to handle a variety of situations. Availability The neat thing about networking is that works on one computer.
Memcached is a great service to cache data. It uses plain-old text commands over TCP to save and retrieve data. You can even telnet into Memcached to debug it. Wireless routers are similar: The router serves up webpages, and when you submit data it makes the necessary configuration changes.
Protocols like HTTP are so popular you can assume the user has a client. Layering Protocols Protocols can be layered. We might write a resume, which is part of a larger application, which is stuffed into an envelope. Each segment has its own format, blissfully unaware of the others.
Web services do just that. Because plain text is ubiquitous and easy to use, it is the basis for most protocols. And TCP is the simplest, most-supported way to exchange text.A basic understanding of networking is important for anyone managing a server.
Not only is it essential for getting your services online and running smoothly, it also gives you the insight to diagnose problems. An Introduction to Networking Terminology, Interfaces, and Protocols Posted January 14, Networking works by piggybacking a.
Understanding Networks Although you are probably taking this class to learn about computer net-works, and some of you probably already know how important networks.
Developing an understanding of how and why networks work, rather than focusing on memorization of terms or numbers as you learn basic computer networking tasks, such as Internet connectivity, configuring connections to an Internet Service Provider, and creating a private network.
Understanding how WiFi works! WiFi, what a great convenient way to connect to the internet while roaming around in your home or workplace. The magical bubble that you never see but know you are connected when you see that WiFi symbol on your device, and most people cannot seem to live without.
Most networking discussions are a jumble of acronyms. Forget the configuration details — what are the insights?
Networking is about communication; Text is the simplest way to communicate; Protocols are standards for reading and writing text; Beneath the details, networking is an IM conversation. 0 PREFACE “No man but a blockhead ever wrote, except for money.” - Samuel Johnson The textbook world is changing.
On the one hand, open source software and creative-commons licensing.