Editing 2105: Modern OSI Model

{{comic
| number    = 2105
| date      = January 30, 2019
| title     = Modern OSI Model
| image     = modern_osi_model.png
| titletext = In retrospect, I shouldn't have used each layer of the OSI model as one of my horcruxes.
}}

==Explanation==
The {{w|OSI model|Open Systems Interconnection (OSI) Model}} is a conceptual model for network communications that defines 7 layers of functionality, where higher layers add increasing complexity to lower layers through associated protocols and standards.  The 7 layers in the standard OSI Model are:

*7.  Application layer: Defines how applications interact with the stack to request and receive information
*6.  Presentation layer: Defines how one or more sessions are used by endpoints to send and receive a packet of information
*5.  Session layer: Defines how communication events are initiated and managed in order to successfully transmit information
*4.  Transport layer: Defines how information is transmitted across the nodes of a network
*3.  Network layer: Defines how nodes are interconnected to form a network of nodes
*2.  Data link layer: Defines how data is transmitted across a wired connection
*1.  Physical layer: Defines the wiring connections between two different nodes

In practice, the OSI model abstracts the communication between two end points, like a Facebook client and Facebook servers all the way from the application layer on the server, down to the wire on which the data is transmitted, and back up to the application layer where the user views the data. As Facebook is one of the most used websites in the world with more than a billion users, Randall claims that the "application" layer (what the client sees and uses) is mostly {{w|Facebook}}.

A light gray shape labeled "Google & Amazon" surrounds all seven layers of the model in an irregular shape indicating that Google and Amazon, by dint of their size and dominance at multiple layers of the model influence the entire structure. An example of Google's influence would be their introduction of new protocols like {{w|QUIC}} and {{w|SPDY}} as replacements for the existing TCP protocol that was a foundation of the web, and their accompanying modifications of the original {{w|HTTP}} protocol.

The significance of the irregular pattern of the "Google & Amazon" blob isn't clear. It is likely that it is in reference to the irregular way in which their modifications to the OSI stack have evolved. Potentially with extensions to the left representing the influence of Google, and extension to the right representing the influence of Amazon. However, it is also notable that the irregular structure of the stack is reminiscent of a {{w|Jenga}} tower. Jenga is a game in which blocks are removed from a vertical stack and added back to the top until the whole collapses. This may be a commentary on the instability of the network stack in general, or on how Google and Amazon's additions and changes to it have destabilized the networking protocols.  Or, the specific blocks to be pulled out (presentation, session, and network) may be the ones whose removal collapses the tower while the other ones can be easily removed and replaced (like the center blocks in Jenga), implying that between Google and Amazon, even if these were pulled out, the tower would remain standing.  What this says about the three layers that would destabilize the tower is unclear.

Another interpretation: Google and Amazon's market dominance is so extreme that (according to Randall) most users only access layers 1 (Physical), 2 (Data Link), and 4 (Transport) through Google and Amazon.  Layers 3 (Network), 5 (Session), and 6 (Presentation), while strongly influenced by Google and Amazon, have at least not been completely swallowed up by those two companies.

The title text refers to {{w|Magical_objects_in_Harry_Potter#Horcruxes|Horcruxes}} used by {{w|Lord Voldemort|Voldemort}} in the ''{{w|Harry Potter}}'' book series. A Horcrux is a magical artifact used to house a wizard's soul, preventing them from dying if their body is destroyed. Since they can only be created by murdering other people, they are heavily forbidden, and before Voldemort it was unheard of for a wizard to use more than one. Voldemort used seven -- the same number of layers in the OSI model. However, while Voldemort hid his seven Horcruxes in different places to make himself that much harder to kill, Randall's have all been collected in Google and Amazon, defeating the purpose of using more than one. Alternatively, transforming each layer of the OSI model into a horcrux may be regarded as a strategy to prevent them from being destroyed since doing so would destroy networking. This strategy would fail in the modern world, since some of the envisioned layers were not used in the more common modern TCP/IP networking model and in the case of cloud infrastructure potential exists to provide even more shortcuts.

The title text may also be a reference to a [[1417|prior comic]] about Randall mixing up things that come in groups of seven, like data layers and Horcruxes.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:'''Modern OSI Model'''

:[A light gray shape that surrounds seven stacked dark gray rectangles, all with labels.]

::Application (Facebook) [supported by the light gray shape on both sides]

::Presentation  [pulling out would collapse the tower]

::Session  [pulling out would collapse the tower]

::Transport [supported on both sides]

::Network  [pulling out would collapse the tower]

:Google & Amazon [label of the light gray shape]

::Data link [supported on both sides]

::Physical [supported on both sides]

{{comic discussion}}