Every device connected to the Internet has at least one unique IP address. The IP address has two parts - the network address and the host address. (How you split the IP address into network and host is a bit tricky for humans to do...)
Q: What has more than one IP address?
Notes
Name resolution
Notes
Domain Name Space (DNS)
Notes
Name Lookup
Notes
Root Server Addresses
Notes
Top level domain Country Code
Notes
Top level domain Country Code 2
la -- Laos Currently being marketed as the unofficial domain for Los Angeles[9]
li -- Also used by Long Island
to -- Tonga: Torrent, Turin, Toronto, Tokyo, or Tocantins
tv -- Tuvalu: television (the domain is currently operated by dotTV, a VeriSign company; the Tuvalu government owns twenty percent of the company.)
Notes
Protocol
Protocol: Layering Model 1
Layering is another innovation that was driven by a philosophy of connection.
Without layering, you designed an integrated network from top down. For example, every component of the (original) telephone network was designed for telephony. Every component of a utility network (think electricity, gas...etc) was designed for a specific use
in mind.
The internet protocol was designed with a different ideology.
Layering is another innovation that is unique. Before, if you
wanted a network, you designed it integrated top down. (Telephone). But once you designed it,
you can't use it to carry gas, or water
If something that has depth has a white cloth on it, it is a bed. That is the definition of a bed.
Application sees a bed. It doesn't care.
TCP (remember routers can drop packets. the job of TCP is to keep track)
The most important is the physical layer is separated.
There are many networking device right - ether net, wi-fi, cell phone. if you have anything that transmit data, all you have to do is right code for the physical layer.
Wok
Lets imaging that you snuck in a cell-phone or a sattelite-phone
into a remote censured village. Now you connect a USB-wireless
device to a Wok and you can send the Internet signal all the way
across the village.
It's very easy to connect to the Internet (or very hard to censure)
because it can connect to so many thing.
Nobody above the physical layer need to know that it is running on a Wok
Notes
iPhone Hotspot
Two physical devices: Cellular & WiFI
Notes
Hyperconnectivity -- Politics in the technological!
Easy to connect different devices (again, very resilient).
Devices can be very poor to very high-end. Doesn't matter. (Compare this with the ideology of telephone networks)
No need to change/modify application.
Chrome will work regardless of whether it is on a wireless network or on a wired network.
Use the bed analogy again.
As far as the application is concerned, it sees a bed and sends
requests only pertinent to the application. (It does not have to
worry about anything about the network whether it is sending
something it using WI-FI or ethernet).
And on the other side, it looks as though something meaningful is coming
out of the bed.
Protocol
Layering allows for layer to layer communication.
From the application's point of view, it only has to think about the application to application communication method.
Communication between web browser and web server:
Using file transfer protocol
Protocol mismatch:
Application does not have to worry about whether it is going through a Wireless network or a wired network
All an application has to do is to worry about how to communicate with other applications. And this is called a protocol
A protocol is a predefined rule on how to communicate with the other end.
ftp, sftp, ssh, http, shttp
manually telnet into web server and show
1. how simple the http protocol is.
2. how it has no concern for lower layers (it doesn't care
whether it is on the cell network or not)