> For the complete documentation index, see [llms.txt](https://sliu583.gitbook.io/blog/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://sliu583.gitbook.io/blog/networking/index/cs-268-adv-network/intro.md).

# Intro

Foundation of global internet 

1972: open network 

* Key arch 
* Interface: plug and play 
* Internet: over-arching notion of how to federate different networks together 
  * A logical framework
  * Layering: learn from early network 
    * Expose: someone can interface different parts of the systems
    * Implementation strategy: modularization 
    * Not a requirement 
    * 1970s: setting layer specification, but nobody implements, just a ref model --> need more tightly-integrated implementation 
  *  Gateway linking? 
    * I.e. routers 
  * Packet: have the system self-configured so it knows what pieces were connected in where
    * Routing protocols 
  * Assumptions on the Internet 
    * Binding of addresses etc. didn't have a lot of mobility back then
    * These assumptions might not hold today (i.e. new applications and new needs) 
    * 1983s: community more evolves --> nobody knows enough on the history to do a arch change 
  * Why don't you make a more secure system? 
    * Technical challenge, will also be social 
    * Edge of the net: where the IP layer ends and the host computer starts, a bunch of interesting protocol happen inside in an end-to-end basis 
      * End-to-end notion: much of the functionalities are in the edges; no permissions from IP part to try things
  * Evolve under different contexts? 
    * One answer 
      * Interfaces that define different protocol layers: stability 
        * I.e. optical fiber, switching tech 
      * Open place to innovate (?)
        * I.e. P2P don't have to standardize by anybody 
    *  The other 
      * Research community involves in the back 
      * Now: internet as a net
        * Business model, what changes to do with customers
        * Originally bottom-up scenario
        * Today: lack of changing things in a big architectural way
          * But big thing is pretty small 
          * What would it take to make a big architectural way? 
            * Happen in incremental changes 
            * Or creation of something completely independent  
      * New technology: new? or replacements? 
        * Grow up in existence of the switching 
        * New techs will co-exist, and run on-top of the internet for a while 
          * Nothing is instantaneously happening
      * Virtual private network
        * Interact through virtual circuit 
  * Applications: sub-optimal 
    * E.x. voice network? 
    * One hand: made to work with lots of different applications 
    * But: remove motivations --> cross-boundaries to make something different 
    * Harder: mobility, identity management and auth strategies; real change in Internet is pervasive (i.e. something beyond the edge, software, hardware, distributed sys, application in some sorts --> whole new set of challenges) 
    * Assumption 
      * Wireless: most of the time disconnected
      * But back then: assumption is that mostly connected 
      * Uniqueness is valuable!
        * i.e. identity
        * But lack of commonality 
        * Network partitioning: move away from the current architecture; maybe the early binding is too tight