Open Architecture Networking
The Internet uses an open architecture networking. Designers are free to design networks however they want. All these networks can communcicate over the internet.
Each network is connected to the Internet through a router gateway.
Within national boundaries, networks belonging to a large business or a unversity connect directly to the national backbone, whereas smaller organisations or individuals connect via an ISP, who are then connected to the backbone
Routers are special switches that recieve incoming packets of data along one link and send that as an outgoing packet to another link. Each packet contains the IP of the destination, which is used to find the destination and to choose the right outgoing link. Each network is connect to the Internet through a router gateway. A router gateway allows one network to be connected to another so that packets from one network can be translated into a form which is compatible to the next A gateway is only necessary when the communication channels on either side of it use different link layer protocols. If the channel uses the same link layer protocol, the machine is just a router.
Gateways regulate traffic between two dissimilar networks, while routers regulate traffic between similar networks. A gateway is only necessary when the communcation channels on either side of it use differernt link layer protocols. If the channel uses the same link layer, a router is used.
Examples of networks
|WAN||Wide Area Network|
|MAN||Metropolitan Area Network|
|CAN||Campus Area Network|
|LAN||Local Area Network|
|WLAN||Wireless Local Area Network|
|PAN||Personal Area Network|
|Bus||All the computers are connected to the same wire, called the backbone|
|Ring||All the computers are linked in a ring, and a token is passed around|
|Star||All the computers are connected to a switch|
|Mesh||All the computers are connected to each other|
|Wireless||Uses electromagnetic radiation to transmit via the power of a WLAN|
The Intranet is a term often used to refer to a private connection of LANs and WANs that belongs to an organisation, and is only accessed via the members of the organisation.
Nobody owns the internet. However, people still does regulate it.
The internet society was established in 1992 to oversee and manage network protocols and systems.
A network protocol is a set of rules that a program folows. This allows for a standardised format of communication.
These rules define:
- How to establish and terminate a communication
- The format of the data being transferred
- Error checking and correction
The most common protocol is the
The protocols that make TCP/IP define how data is transferred over a network. Programs use TCP/IP to make up network protocols.
End node verification
TCP/IP is decentralised.
Protocols that use TCP/IP
|SSH||Secure Shell||22||Remote control command prompt|
|Telnet||Terminal Emulation Link Network||23||Remote control command prompt|
|POP3||Post Office Protocol Version 3||110, (465)||Emails!|
|SMTP||Simple Mail Transfer Protocol||143, (993)||Emails!|
|HTTP||Hypertext Transfer Protocol||80||A protocol which transfers files, such as HTML to be viewed in a web browser.|
|HTTP2||Hypertext Transfer Protocol Version 2||80||A second version which allows for more simultaneous requests to occur.|
|HTTPS||Hypertext Transfer Protocol (Secure!)||443||The same as HTTP, but wrapped up in a cozy shell of SSL|
|FTP||File Transfer Protocol||21||Move files across the internet!|
|SMB||Server Message Block||Move files across the intranet! Also contains other Mircosoft things.|
|WebDAV||Web Distributed Authoring and Versioning||80, 443||Move files across the internet! An extension to
|SFTP||Secure File Transfer Protocol||22||Move files across the internet! Uses
|CSMA/CD||Carrier-sense Multiple Access (with) Collision Detection||If there is a collision, send a packet after a random time, up to 60 seconds before discarding a packet.|
|CSMA/CA||Carrier-sense Multiple Access (with) Collision Avoidance||Send a packet after a time period|
A MAC address, or a (Machine Access Code) allows for the TCP/IP to transfer data to the correct computer. This MAC is hard-coded into the physical network interface card.
Name servers store the mapping information between IP addresses and Domain Names. This data is stored within a DNS server.
All data transmissions are checked for corruption, and have ACKnowledgements.
Ports are logical "pipelines" which allow for multiple applications to communicate simultaneously.