04 March 2009

Seven layer ISO stack, plus two

The Seven layer OSI model stack -- an ISO standard, palindromically -- characterizes how computer and data network (and thus internet) applications communicate between separate computers in a defined fashion. From the bottom up: Physical, Data Link, Network, Transport, Session, Presentation, and Application layers

Computer networking geeks use that the seven-layer stack, to specify and to analyze matters running from what a given voltage level means at the bottom (Physical layer), to how a email client retrieves email from a mailstore at the top (Application layer).

In preparing this piece, I find see reference some to mnemonic forms to get the sequence of the Layers correct that I did not know before:
The mnemonics "People Design Networks To Send Packets Accurately", "Please Do Not Throw Sausage Pizza Away", and "All People Seem To Need Data Processing" may help you remember the layers.
BambooWeb article

Some wags extend the definition thus:
Of course, above those seven layers are two more: the Financial, and the Political Layers, which also need to be functional.

The dis-functionality and friction of office politics, or perhaps of being unable to get funding needed for a more reliable and functional network infrastructure rather than a Bigger, Newer, Better computer to sit unused on a pointy headed boss' desk, each come to mind as obvious examples. In wider scopes, Financial may encompass Economics and Markets; Political expands to social interaction, policy and polity

It seems in at least one restatement, to also have added an explicit 'religious' layer as well under some restatements. I think one can perhaps subsume Religious into Political, but I can see the genesis of the historical tension to draw a difference between those asserting dominion over a person's earthly presence, and spiritual corpus.
Network technicians will sometimes refer euphemistically to "layer-eight problems," meaning problems with an end user and not with the network.

Carl Malamud, in his book [1991] book"Stacks," defines layers 8, 9, and 10 as "Money", "Politics", and "Religion". The "Religion layer" is used to describe non-rational behavior and/or decision-making that cannot be accounted for within the lower nine levels. (For example, a manager who insists on migrating all systems to a Microsoft platform "because everyone else is doing it" is said to be operating in Layer 10.)
BambooWeb article

I see also that people have adapted use of [pdf] the Political and Finacial Layers. No model is so good it cannot be twisted, abused and extended, it seems

Anyway, I lay this foundation to provide a kick-off target to point back to in future discussions of the Political and Financial layers of the stack