Internet Infrastructure and Technologies

Internet Evolution and Autonomy

The Internet was initially managed by DARPA, but it became too large and unmanageable.
DARPA handed it off to the National Science Foundation (NSF).
The NSF, in turn, developed a system for the Internet to run autonomously.
The result is the autonomous Internet we have today.

As the Internet grew, it became impractical for every company to connect directly to every customer.
To facilitate information exchange, Internet exchange points (IXPs) were created.
An IXP is a physical location where different tiers of ISPs connect to each other, allowing them to exchange traffic.

When one ISP (e.g., AT&T) delivers the last portion of an email to a recipient on another ISP (e.g., Sprint), and vice versa, they are essentially doing work for each other.
To avoid billing complexities and potential taxable income, ISPs often enter into peering agreements.
A peering agreement is a gentleman's agreement where ISPs agree not to charge each other for exchanging traffic, assuming that the traffic volume is roughly equal.

ISPs connect to customers by getting as close as possible to their location; this connection point is referred to as the point of presence.
The local loop, also known as the last mile, is the final connection between the ISP's point of presence and the customer's premises.
It doesn't necessarily represent a mile in distance; it's simply a term indicating the proximity of the connection.
The local loop can connect to a local telephone exchange or directly to the ISP's system.

Voice over Internet Protocol (VoIP) emerged, enabling free phone calls over the Internet, which threatened the traditional revenue model of phone companies (AT&T, Verizon, and Sprint).
To adapt, these companies acquired cable companies, gaining control over Internet access and charging for it.
Cable companies traditionally used coaxial cable networks, but these companies are transitioning to hybrid fiber-coax networks and ultimately aiming for fiber to the home (FTTH).
FTTH involves replacing the entire network, including the local loop, with fiber optic cables for faster speeds.

Currently, data is sent over fiber optic cables using a single laser beam, requiring packet data units (PDUs) to be transmitted in single file.
The goal is to use multicolored lasers within fiber optic cables, creating multiple lanes (e.g., a thousand lanes with a thousand colors).
This would allow PDUs to be transmitted simultaneously, significantly increasing the overall data transfer rate.
While the speed per PDU remains the same (speed of light), the total throughput increases dramatically.

Even with fiber optic infrastructure up to the home, copper cables within homes and businesses can become a bottleneck, limiting the potential speed.
Fiber in the home (FTTH) involves replacing copper cables inside buildings with fiber optic cables to fully utilize the increasing Internet speeds.
Ideally, fiber optic cables should be installed during construction, but for existing buildings, they can be placed in attics.
Currently, fiber is relatively expensive, and the demand for higher speeds is not yet universal, but eventually, it will become necessary to fully leverage Internet capabilities.

When an ISP installs Internet service, they typically provide equipment such as a router and modem.
Customers can choose to use their own equipment, but most opt to rent it from the ISP for a monthly fee.
ISPs often write off the cost of CPE within the first year, treating subsequent rental payments as pure profit.
Customers should periodically review their bills to ensure they are not being charged for equipment they have returned or are not using.
CPE can become outdated quickly, similar to other computer equipment.

CPE acts as a line splitter, dividing the incoming signal into different streams for phone (VoIP), television, and Internet.
ISPs also use line splitters at their main distribution facility (MDF) to separate and route the various services.

WiMAX is a technology that uses microwave frequencies for wireless Internet access.
Sprint and Clear Communications have used microwave technology.
Only one provider can operate in a given area to avoid interference.
WiMAX requires a dish antenna pointed at a microwave tower.
Speeds can reach 40-70 megabits per second, but performance can be impacted by obstructions such as buildings, hills, and trees.

Satellite Internet provides a direct connection to a satellite, offering better line-of-sight compared to microwave.
Radio frequencies are used for Wi-Fi and cell phone connections.
Microwave is essentially a high-frequency radio wave and it is given a different name.

Internet Society: An open society promoting the open development, evolution, and use of the Internet for the benefit of all.
Internet Engineering Task Force (IETF): A technical organization focused on researching and solving Internet-related problems, such as bottlenecks and conflicting protocols.
- Issues requests for comments (RFCs) to solicit feedback on proposed solutions.
Internet Engineering Steering Group (IESG): Manages the IETF and oversees organizations like ICANN (Internet Corporation for Assigned Names and Numbers), which handles domain name assignments and the shared registration system.
Internet Architecture Board (IAB): Addresses structural problems of the Internet, such as vulnerabilities to disasters or single points of failure. For example, the concentration of transatlantic cables in a single building in New York City.
Internet Research Task Force (IRTF): Focuses on long-term solutions to Internet issues through small, focused research groups.

The current Internet was previously known as NGI (Next Generation Internet) during its development.
The term