Packets, TCP/IP, HTTP&HTML

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Created by
Xuan

Cards (37)

  • Information in the internet is broken down in to chunks known as packets when departing and reassembled upon arriving
  • The amount of time it takes a packet to travel from the source to the destination is called the latency or ping
  • The maximum transmission unit (MTU) of an IPv4 packet id 64KB. 1GB file would need to be broken down into 15 625 packets, even more than that, since headers take some space too
  • An IPv4 packet headers consumes 20 bytes and contains source IP addy and destination IP address, and more
  • Header information is public. Routers use this information to direct packets into destination
  • Packets can take different routes and come at different times
  • The Transmission Control Protocol, used in conjunction with IP can be abbreviated TCP/IP
  • TCP/IP is the conceptual model and set of communications protocols used by a majority of internet traffic
  • Data in the TCP/IP model passes through 4 transformative layers before leave for the destination
  • layers of a TCO/IP model: application, transport, internet, link
  • data will travel through the layers in reverse when reaching the destination
  • The data within the packet is often encrypted to prevent packet sniffing
  • Packet Sniffing is the process of intercepting packets on a network to read their contents
  • HTTP stands for HyperText Transfer Protocol
  • The openness of header information is how Internet Service Providers are able to throttle the particular services
  • ISP can't decrypt packet's contents, but can inspect the packet's headers
  • Net Neutrality demands ISP that all internet traffic be treated equally, regardless of the source or destination.
  • User Datagram Protocol (UDP) is another popular protocol that is used for sending small packets of data, used in place of TCP in the Transport Layer
  • UDP has smaller packet size (pro)
  • UDP header contains 8 bytes
  • UDP don't need connection to create and maintain; has more control over when data is sent
  • TCP is reliable while UDP isn't
  • UDP's 16-bit checksum: when corruption detected, said segment most likely to be discarded, or has a warning. If a packet get dropped, it's gone. Packets are out of order, won't stop even if network is congested
  • UDP is used by low-latency applications
  • URL stands for
    Uniform Resource Locator
  • When you enter a URL into a web browser, you are making HTTP (HyperText Transfer Protocol) GET request. All you are doing is requesting a file from a server: another computer designed to distribute said file.
  • HTTP is the protocol that allows your computer to communicate with servers on the internet
  • HTML is the standard markup language for documents designed to be displayed in a web browser.
  • HTML defines the structure of a web page through HTML elements: pieces of content  wrapped in opening and closing tags.
  • The <!DOCTYPE html> declaration is used to inform a browser that the document being rendered is an HTML document.
  • <head>

    </head>
    Information in this section is not rendered on the webpage but carries important information about the document...
  • When you visit a website that uses cookies, data is stored on your computer.
  • A “zombie cookie” is a cookie that recreates itself after being deleted, making zombie cookies tough to manage.
  • A supercookie is a type of tracking cookie inserted into an HTTP header to collect data about a user's internet browsing history and habits.
  • HTML is technically a markup language, not a programming language.
  • A markup language is a set of rules that can be used to format the presentation of documents.
  • The biggest difference is a markup language lacks the ability to make decisions via conditionals such as if-statements and loops.