Internet Architecture
The internet began as a research project in the early 1960s funded by DARPA (Defense Advanced Research Projects Agency). DARPA hoped to develop a method for linking multiple computer networks, allowing them to function as a single system unaffected by disasters degrading the performance of local components.
Internet Service Providers
Internet Addressing
Internet networking systems use addressing systems to assign a unique identifier to each computer in the network
The Internet uses internet protocol (IP) addresses as unique identifiers.
- uses two formats:
- ICANN manages ISP IP address assignment
Domain Name System(DNS)
Internet Applications
In the earlier days of the internet, most applications were simple programs that followed a network protocol.
Network protocols are rules, procedures, and formats that govern the communication of multiple devices over a network.
- ensures timely, secure, and managed network communication
As web servers and browsers became more sophisticated, traditional networks became handled by web pages using the powerful hypertext transfer protocol (HTTP).
Simple Mail Transfer Protocol (SMTP) is a network protocol that supports email transmission.
- Uses DNS lookups to identify the recipient of the email and send the message over the internet to a mail server
- Then retrieved using protocols such as POP3 (Post Office Protocol version 3) and IMAP (Internet Message Access Protocol)
VoIP (Voice over Internet Protocol) is used for voice communication over the Internet.
- operates by establishing a connection between two devices and then performing real-time, two-way transmission of audio data
- Softphones allow two or more computers to share a call without any additional hardware
- Analog telephone adapters allow users to connect their physical phones to a port that digitizes and then transmits real-time audio data
Streaming is transporting audio and video data across the Internet in near real-time.
- Large-scale streaming services use content delivery networks (CDNs)
CDNs are groups of servers distributed strategically over the internet that stream copies of content to nearby end users.
- anycast enables an end user to connect to the closest server automatically