OSI Layer 7 – Where Freedom Takes a Detour

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So up to this point, we’ve highlighted the wonky technical stuff illustrating just how resilient the Internet is. And how intentional that resilience is. There is a tremendous amount of intelligence and money applied to make sure that communication amongst many entities can happen, no matter what.

Now we arrive at the final layer, the application layer, and we will feel right at home at this layer. This layer is where humans interact with the technology. It’s where bazillions of dollars are made. It’s where all the magic happens and what all the fuss is about. Without layer 7, none of the other 6 layers matter.

The first major applications were things like:

  • Telnet (1969) which allowed users to remotely access a computer system as if they were sitting in front of it.
  • Email (1971) created by Ray Tomlinson, which upgraded his prior mainframe-only email to work over the network.
  • FTP (1971) File Transfer Protocol, somewhat self-explanatory
  • Usenet (1979) a bulletin board like system that allowed users to post, read, and reply to public messages
  • IRC (1988) by Jarkko Oikarinen, Internet Relay Chat allowed users to join chat rooms and interact with each other directly.
  • Gopher (1991) by Mark P. McCahill, was a spiritual pre-cursor to the web, allowing users to find documents.
While initially proving popular, the Gopher protocol has largely disappeared. With around 300 servers that will never quit, ever.

These early applications laid the groundwork for the rich ecosystem we have today. However, they were relatively static and specialized in their functions. Each served a specific purpose: Telnet for remote access, Email for messaging, FTP for file transfer, and so on. While groundbreaking for their time, these applications were limited in their flexibility and scope.

Then came the game-changer: HTTP (Hypertext Transfer Protocol) and the World Wide Web.

Developed by Tim Berners-Lee in 1989 and publicly released in 1991, HTTP and the web created the ultimate flexible addition to Layer 7. Unlike its predecessors, the web wasn’t designed for a single, specific purpose. Instead, it provided a general-purpose platform that could be adapted for almost any type of application.

What made HTTP and the web so revolutionary was their simplicity and extensibility:

  1. Hypertext: The ability to link documents (which eventually became pages ) together created a web of information, allowing users to interact with documents.
  2. Statelessness: Each request-response cycle is independent, which simplified server design and allowed for easy scaling.
  3. Content Types: HTTP could serve various types of content (text, images, audio, video), making it incredibly versatile.
  4. Client-Server Model: This separation of concerns allowed for rapid innovation on both ends.

The web’s flexibility meant that developers could create applications that were previously unimaginable. Suddenly, you could have:

  • Online stores (Amazon, 1994)
  • Search engines (Google, 1998)
  • Social networks (Facebook, 2004)
  • Video streaming platforms (YouTube, 2005)
  • Microblogging services (Twitter, 2006)

All of these diverse applications run on the same underlying protocol and infrastructure. This flexibility allowed for rapid innovation and democratized app development. Anyone with a basic understanding of HTML and a web server could create content accessible to millions.

Moreover, as web technologies evolved (with the introduction of JavaScript, CSS, and more sophisticated backend technologies), the web became even more powerful. Modern web applications can do almost anything a desktop application can do, from complex data processing to real-time communication.

Layer 7 is incredibly flexible. It’s the wild west of the OSI model, where applications can do pretty much anything they want. Want to create a social media platform? Layer 7. A video streaming service? Layer 7. A decentralized cryptocurrency network? You guessed it, Layer 7.

This flexibility and power is a double-edged sword when it comes to freedom and democracy. On one hand, it has given voices to millions, allowed for the free flow of information on an unprecedented scale, and enabled incredible innovation that can empower individuals and communities. On the other hand, it has led to massive, centralized platforms that now control much of our online experience, with near-total control over what they present to us.

So despite this flexibility and capacity for innovation, we’re increasingly using fewer and fewer sites for more and more of our online activities. Facebook, Google, Twitter, TikTok – these giants have become the primary gateways through which many people experience the internet. This concentration means these limited sites have an outsized influence on what information we see and how we interact online.

This is all because of something called Metcalfe’s Law. This law states that the value of a network is proportional to the square of the number of connected users. In other words, the more people use a site, the more valuable it becomes due to the network of people it provides. This creates a powerful feedback loop – people join because that’s where everyone else is, which makes the site even more attractive to new users.

Metcalfe’s law, showing the value of a network (and the number of cat memes) as the number of users increases. (source R Uzwyshyn)

So as use of these centralized websites increases, their ability to control content also increases.  They have used this power in questionable ways, even colluding with the government to determine what people see.

But while some have tried to sue  and others have tried passing laws, the real answer lies in the technology itself.  While layer 7 makes it possible to censor a single site, the rest of the OSI ‘stack’ makes true censorship nearly impossible.  “The Net interprets censorship as damage and routes around it.” (A quote attributed to John Gilmore in the early 90’s.)  And the ability to route around it is significant.

Next we’ll talk about ways the internet could heal itself from it’s current ailments.

OSI Model Layer 3 and 4, Freedom and Democracy

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Layers 3 and 4 are then “network” and “transport” layer, respectively.

While layer 1 and 2 had to do with local traffic, the next two layers create the standards and protocols by which all these local networks can talk to each other (“internetworking”).  They scale to a global scale.

OSI Layer 3 – Network Layer

The network layer that currently dominates the world is the IP protocol.  Nearly everyone has heard of an IP address by now, probably in frustration as they tried to configure a home device or internet connection.

The power of the IP protocol is in its superior route-ability.  There have been other protocols that work well in certain circumstances, but IP proved to be the brilliant solution that literally created the internet.

IPs superior routability stems from it’s super simple addressing scheme, in which you take a bunch of numbers (an address), apply another set of numbers (called a mask) and end up with a neatly sliced network-host dileneation.

Old School Computing
I’m pretty sure that’s a subnet cheat-sheet.
Photography: Yves Tessier 1972

You can think of the network as the street you live on, and the host as the house in which you live.  In the following examples, the blue is the network/street, and the red is the host/house.

3472 Oak Street

10.29.44.6

But IP addressing is far more powerful than a street address, in that the networks can then further be sliced up using masks.  A mask is another set of numbers that defines which part of the address is being addressed.  So you could further say:

Cleveland, Ohio

10.28.44.6

Where orange is the locality and green is the larger area.  This slicing can get even more granular and complex as needed.

I won’t risk complicating a simple and elegant system in trying to address it in one blog post.  But the upshot is that millions of devices called routers can reliably and effectively transport huge amounts of data through multiple other routers and back.  It’s not uncommon for traffic to go through 10-20 routers on its way to a destination.

OSI Layer 4 – Transport Layer

Layer 4 is the layer that defines a conversation.  Take this human example of TCP (Transmission Control Protocol):

Sally: Hello is this joe?

Joe: Yes!  This is joe.

Sally: Great!  Here’s some info…..*garbled*

Joe: I’m sorry, can you repeat that?  Also can you speak a little slower?

Sally: Sure…here…is….some…information…for you.  Did you get that?

Joe:  Yes I got it. I will deliver it to the appropriate party.

Operators
While this pictures not a perfect analogy, TCP is responsible for making connections between IPs, making them appropriately, and ensuring that no information is garbled or lost.
Src: Seattle Municipal Archives

This conversation is a representation of a TCP conversation that happens trillions of times a day.   In contrast, here’s an example of UDP (User Datagram Protocol:

Sally:  Hey, I’m shouting this to Joe!  Joe, if you can hear me here some information for you!

loudspeaker
In contrast, UDP is a way to send a message to another machine without a connection or any guarantee that they will hear it, or hear it clearly.

Both of these conversations do essentially the same thing, but with a different set of requirements.  These requirements are defined by a layer 4 protocol.

Across layer 3 and 4, there are several protocols and combinations of protocols that assist communication.  They help control speed of transmission, choosing the best route between hosts, and several other critical functions that help ensure data gets from point A to point B.

Implications for Freedom and Democracy

The creation of a redundant, reliable packet-switched (vs. circuit-switched) network of communications was created for two reasons.  First, the number of computers in the world was very small, and people needed access to them without being physically present.  Second, the military needed a way to maintain control of nuclear resources and communications in the even of a nuclear war.

These two goals are somewhat in dispute.  And that makes complete sense given the supply of movie plots where scientific discovery was unwittingly being used for the military.   It’s pretty obvious that everyone involved had their own goals in mind.

Outbreak Monkey
Like the internet, both man and monkey in the movie Outbreak were either a military asset or a way to save the world. But in reality they were both.
Src: Warner Bros

But, the implications for today are clear.  Using these technologies, you can send data reliably from a very localized device to another very localized device anywhere around the world.  We are seeing this play out now in Ukraine.  This is a unique enough situation that I will post about it separately.

Because these systems were designed to create access via large scale, they ensure that anyone in the world can communicate with another.  They can do this directly and without reliance on a mediator or central 3rd party.

Because these systems were designed, at some level, to survive nuclear hostilities, they are inherently robust and redundant.  Getting in the way of these connections is very hard.

Freedom loves communication and the free flow of information.  Indeed, it depends on it.  Layers 1-4 are great enablers of freedom.

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OSI Model Layer 1 and 2, Freedom and Democracy

So let’s look at the first 2 layers of the OSI model.  These are the “Physical” layer and the “Data Link” layer.  These layers are separate and distinct, but in practical application they are usually part of the same implementation.

The physical layer (layer 1) is, as it implies, concerned with the physical elements of a connection.  Voltages, pin-outs, mechanical considerations, connectors, etc.  In the case of fiber optics, it deals with wavelengths and supported configurations such as single or multi mode.  Because it is physical, this layer tends to be focused on local networks or networks with fewer participants.

Because of the radically different technologies out there at the physical layer, there is not really a standard unit of data.  It can be very different depending on topology.

The IMP router
The very first router. While it technically includes layer 3 functions, this is the first device that let computers communicate at layer 1 and 2. (1969)

The Data Link layer (layer 2) defines the formats of data that will be communicated on top of layer 1.  How data is divided up into chunks, how things on a local network will be  addressed (such as MAC addresses), and how a system will know what chunk of data belongs to which device.  These are usually called “frames”.

For layer 1 and 2, most people will have used twisted pair ethernet or various forms of WiFi.  If you used a computer at work in the 80’s or 90’s, you may have used other forms of Ethernet or even Token Ring.  If you’re really fancy, you may have fiber ethernet coming to your house.

Whatever the case, the implication for freedom and democracy is interoperability.  Layer 1 and 2 ensure that your devices can talk to each other at the most basic level.

Ethernet Frame
An Ethernet Frame. When your coffeemaker talks about you to Alexa, this is the picture it uses.

Information is very important to freedom and democracy.  Indeed, it’s why the 1st amendment exists and has been upheld and bolstered as technology advances.  Being able to consume and produce information freely is vital to the concept of liberty.

We forget than not too long ago our television, our record player (or 8-track!), our camera, our phones, and anything else all lived in separate worlds.  You couldn’t listen to a podcast or stream a news channel across the platform of your choice.  Or, more importantly, you couldn’t make a podcast or vlog from the platform at all.

Layer 1 and layer 2 interoperability allows your phone to stream a video connection to loved ones.  It allows you to listen to a podcast.  If you don’t like the selection of news channels, you can download and view another in the local medium of your choice.

You could buy a bunch of cool stuff in 1989, but very few things talked to other things. Src: radioshackcatalogs.com

It makes it extremely easy for manufacturers to create cheap and reliable tech that allows all of this.  If one tries to make things too proprietary, other things wont’ work with it.

(Having said that, you can also see the creators  intent and values of layer 1 and 2 technology.  If you’ve ever setup an ethernet network or even a more modern WiFi network, it’s still a pretty localized technical process.)

Layers 1 and 2 are important because they are closest to us.  And the bring the concepts of electronic freedom into our living room.

Next articles:

The OSI Model, Freedom, Democracy, and Message

If you got this far past the title, you’re either a techie, or really bored, or both.  But I think it’s a really important juxtaposition in understanding the current state of things.

Marshall McLuhan coined the term “The medium is the message” in the 1960’s book Understanding Media: The Extensions of Man.  I haven’t read this book yet, although I’ve ordered it.  I have watched a few of his interviews.

iphone is the message
There are many people who say that we’re just now catching up with McLuhan’s ideas.

McLuhan’s point was that the overall effect of a communication medium is far more important that the specific message conveyed.  The effect of television on humanity is for more important than a television show.  An example I can think of from my generation is that MTV’s effect on youth was not so much based on the content, but on the overall effect of television’s ability to capture the attention of people our age and change our thoughts and values.

This thought emerged from the primordial ooze of electronic communication in the 1960’s.  How profound is the message today?  Just look around at people staring at their phones, or the number of phones hoisted in the air during a concert.  Is what the people recording or reading nearly as important as the effect the smart phone has had on everyone?  I look forward to reading more of McLuhan’s work.

cell phone mona lisa
At the last minute, a 500 year journey from canvas to eyeball can be interrupted by another person’s attempt to capture a moment. The war of mediums.
Photo: Jill Evans

I have personally found this assertion directly observable in the creation of this blog.  Even after 2-3 blog entries I’m experiencing an increase in wonder and learning that I had back 20 years ago when the blog concept first manifested.  This form of electronic medium seems to have a positive effect on me, at least.

So to connect dots with McLuhan,  I am delving into my own related theory of tech with this blog: The intent of the creator, and values of the creator, have significant effect on the capabilities of a created technology.  And further, if we understand the intent and values of the people who created the technology we can apply this info in ways that help us fulfil our own goals.  This seems obvious but hopefully I’ll demonstrate that it isn’t always obvious.  (It’s probable that none of this is original thought.  I just haven’t found it illustrated anywhere else yet.)

USB
USB was intended to improve interoperability of peripherals. The creators also wanted us to know we could fail a 50/50 chance 100% of the time.

The 3rd critical idea that enters this arena is the Open Systems Interconnection (OSI) model.    The OSI model is a conceptual model that helps design and explain interoperability between systems.  It is a good way of separating and identifying the technologies that are a part of nearly every aspect of our lives ‘these days’.

Because the OSI model describes 7 layers of communication medium, we can use it in concert with the prior concepts to start to figure out what happened, what’s currently going on, and where it can all lead.  We can do this at all 7 levels.  (And I’ll argue that there’s an 8th.)

Let’s squish all this together.  We can parse the building blocks of our electronic experience using the OSI model.  We can then use some of McLuhans ideas to analyze the effect of each of these aspects.  We can also look at the intent and values of the creation/creators to gain further insight into how the mediums can be implemented or re-implemented.

Maybe we can identify some of the negative things happening, and come up with ways to fix them.

How it Started. The Early Phases of the Internet and Freedom

From a conceptual standpoint, the Internet developed from the ground up starting in the early 1900s.  It started with theories of information and hard science (voltages, frequencies, and the like), that went really deep into math and science in ways that will give you tremendous respect for that $99 router at best buy.

Claude Shannon
One of the creators of information theory, Claude Shannon, explains why your neighbor’s microwave shouldn’t interrupt your Netflix stream. Photo: Nokia Bell Labs

The efforts then moved into methods of connectivity as the Cold War started in the 50’s and 60’s.  It was during this time that a middle layer of building blocks was created, which ensured robust connectivity and flexibility in the network.  After many different efforts and competing theories, the TCP/IP standard was implemented on January 1, 1983.

Vint Cerf and Bob Kahn
Vint Cerf and Bob Kahn, creators of TCP/IP. And destroyers of the poorly dressed computer scientist archetype.
Photo: The Franklin Institute

When the Internet was opened to the public, the upper layers developed in earnest.  Some early protocols like SMTP (email) and FTP (file transfer) were updated and still exist.  Others, like Gopher, were replaced by HTTP and the now-ubiquitous World Wide Web in 1991.  Protocols that were easy and effective survived.  Others were updated or dropped.

NeXT First Web Server
The very first web server. Sir Tim Berners-Lee’s NeXT server.

(Techies out there will see that this process was really about climbing the ladder of what is now called the OSI model.)

The takeaway here is that the Internet developed like this:

  • How can we make something that works using physics, electricity, and connectivity?
  • How can we arrange this thing so that it works well even when powerful entities don’t want it to work at all?
  • Now that everything is connected, how can we share information in a way that accessible and easy on a huge scale?

It was in this 3rd bullet point where things started to go really well.  As we shall see in subsequent posts, it was also where the seeds of censorship were sewn.

As the use of the Internet via the World Wide Web quickly (but also slowly) exploded, finding information was about to become an issue.   The Web was a library of documents with no organization and no index.  Think of a stack of 100 unlabeled books in a dark closet and all you have is a flashlight to find what you’re looking for.

The problem was so obvious that multiple entities began solving it in multiple ways when the web was but a flicker in a PhD’s desktop.

Jumpstation went live in 1993 when the total number of websites was less than 200.

Webcrawler, Lycos, and Excite followed in 1994.  When the total number  of sites grew to around 20,000.

Altavista and Yahoo started in ’95-’96 when the total number of sites was still well below 500,000.

An archive.org screenshot of Yahoo from 1996.
Yahoo was originally called “Jerry’s Guide to the World Wide Web”.

Dogpile and AskJeeves started around ’96.  And, of course, the 1-Trillion-plus gorilla of Google started in 1998 at the dawn of the d0t-com era.  By then the number of web pages was well into the millions and tens of millions.

An undefinably large amount of work by brilliant individuals had created the ultimate information sharing tool.  In around 80 years, humanity had gone from theory on a page to an invention that had the potential to fundamentally change the direction of our history.

But it would also do so by subtly changing fundamentals and definitions that had been taken for granted for quite a while.  In making so many connections, we had created a very dynamic vessel for defining and changing what things mean.

This change could include the very intent of the invention and purpose for inventing it.