Networks

    • 1 bit is a boolean
    • 1 byte = 8 bits

    • 8 million bits = 1 MB

    • To transfer you send one electric pulse.

    • To transfer you omit the electric pulse and this has to be in a time frame. eg. bit per second
    • Bitrate: the number of bits per second a system can transmit
    • Latency: time it takes for a bit to travel from sender to receiver

    Transfer medium

    • Electricity through copper wires eg. Ethernet, is cheap but has a lot of signal loss.
    • Light is faster, minimal signal loss, can be transferred by fiber-optic cable.
    • Radio waves are used for wireless transmission

    Domain name mapping

    • record maps a domain name directly to an IP address (preferred)

    • record maps one domain name to another and are less flexible.

    • When a hacker breaks into a DNS Server and changes a domain name cache to point to a different IP address.
    • Data is chunked into packets and each of these travel in different routes from sender to receiver.
    • The packets my arrive to the receiver at different times but the receiver will wait untill all is ready to assemble.
    • each packet contains it’s IP address of where it came from and where it’s going
    • if one of the network routes is congested, the router might send the packets in different routes and in different order
    • Routers are computers dedicated to forward packets to their destination and balance the network traffic
    • The diversification of routes makes the internet reliable and difficult to take down

    TCP (Transmission Control Protocol)

    Manages all your sending and receiving your data as packets

    • TCP makes sure all packets arrived and send a confirmation status to the sender.
    • If there are any packets missing, TCP will request the sender to re-send those packets.
    • the internet is open
    • all connections are shared
    • information is sent in plain text

    URL (Uniform Resource Locator)

    HTML (HyperText Markup Language)

    SSL (Secure Sockets Layer)

    • adds a layer of protection to the HTTP connection to prevent sniffing and tampering