Routing:
the process of selecting paths in a net along which to send the traffic.
        Global
                link-state algorithm
                each node knows every other node
        Decentralized
                distance-vector algorithm
                each node knows only its neighbors
        Heirarchical
                regions
                a node knows about its neighboring nodes and other regions
Delivery Semantics
        unicast
                one node to one node
        broadcast
                one node to all others
        multicast
                one node to a group of nodes
        anycast
		etc
basic http authentication
protocol-
	computing
		convention or standard that enables the connection between two endpoints.
	politics
		rules which guide how activities are performed - ie diplomacy
components of protocol
	agreement
		between nodes via contract interface or implementation
	encoding
		the process of transforming information from one format to another
	transmitting
		sending packets across edges
	decoding
		a complementary process to encoding
layers of internet
	application 
		http smtp ftp 'the web'
		responsible for preserving the content of the data
		no concern for establishing network connections
		nor sending data between connections
	transport
		tcp
			Transmission Control Protocol
			concerned with two endpoints, not with routing
			error-checking, redundancy
			makes sure the data arrives at its destination correctly
			responsible to resend data if t gets lost
			"are you still there?"
		udp
			User Datagram Protocol
			no implicit handshake
			packets may be dropped, arrive out of order, duplicated, etc
	internet
		ip
			actual movement of data from one place to another
			no interest in content or lost data
			responsible for routing
			fragmentation may occur across nodes
			lower-level transmissions as data moves across the internet
	link
		hardware
		cat-5/6, optical
source ---(data)---> target
TCP connection establishment
1. a ---SYNchronize--> b 
	"hello"