Rainbow Unit: Networks Big and Small
2B: The Infrastructure of the Internet
Technical Overview
The hardware infrastructure of the Internet happens at layers 1 and 2 of the OSI model. Layer 1 provides the cable and radio wave that interconnect devices, along with the installed within the computing device to which media connects. When formally connected to an network the NIC becomes a on the network. Layer two of the OSI model provides the identification mechanisms for the node. A computing device can have one or more than one NIC. For instance, your laptop may be simultaneously connected to a network with both a wired Ethernet media & NIC and a Wi-Fi media and NIC, and your smartphone to a cell radio wave media and NIC and also a Wi-Fi media and NIC. Each NIC is uniquely identifiable so that information is correctly disseminated to the appropriate device. To direct the flow of information between nodes, there must be an or a combination of devices to facilitate communications. The only exception is when two nodes use the NIC, node identifiers, and media to do direct peer-to-peer communications.
Computer Network Building Blocks
There are four main components needed for a computer or other computing device to join as a node on a local area network (LAN) within a building such as a home, library, office, or cafe.
Node Identifier
Any device directly connected to the network that has been assigned a unique identifier on that network. Examples include:
- MAC address (also known as the hardware, physical, or Ethernet address): The serial number for Ethernet cards.
- IP address: The address used by the Internet protocol.
Network Interface controller (NIC)
The hardware necessary for a node to connect to a network. Examples include:
- Ethernet controller (wired Cat5/Cat6 or wireless/Wi-Fi): Used for LANs.
- MODEM (cable, DSL, dialup): Used for traditional internetworking with the Internet.
- Optical Network Terminal (ONT): Used for fiber to the home Internet.
Media
The communications technology used to connect nodes. Examples include:
- Copper transmits low-voltage electricity (e.g., wired Ethernet, DSL, cable, dialup).
- Fiber optic transmits light (e.g., fiber to the home).
- Radio waves (e.g., wireless Ethernet or Bluetooth).
Interconnect Device
A device used to interconnect nodes. Examples include:
- Switch or hub: Wired Ethernet LAN.
- Access point: Wireless Ethernet (Wi-Fi) LAN.
- Router or gateway: Builds an Internet by connecting different LANs together.
- Hotspot:
- A popular alternative term to access point on a Wi-Fi LAN; or
- A mobile device (e.g. Smartphone, Coolpad Surf, NetStick USB Modem, or MiFi 8000) that is both a cell-based wireless router and a Wi-Fi access point providing Internet access through the cell-based Internet connection.[1]
Nodes interconnect with other nodes in different ways, depending on how far they reach geographically, how many people are meant to use them, and who primarily owns or controls them. Some cover a very smal