Backbone or Last Mile? — TechKnowSurge

About this interactive

The internet grew from a few computers on a hub, to networks joined by routers, to companies that offered to connect other people's networks. Those companies then joined their own networks to each other, with redundant links, and so on until there was a global network of networks. No one company owns it, and no one can map all of it, which is why diagrams draw it as a cloud. Some of the companies laid fiber optic cable along the ocean floor between continents; satellites link places too, with more delay because the signal goes to space and back. The main highways that tie all of this together are the backbone. Laying them is very expensive (route planning, material, rights of way), but so many users share them that each user's share of the cost is small. To reach the internet you connect through an internet service provider, an ISP, which links you to the backbone. The expensive part per user is the last mile: the line from the ISP to one house, which serves only that customer. So ISPs reuse whatever already reaches the house. The phone line carries DSL; the cable TV line carries cable internet; newer homes may have fiber run to them; and where none of those reach, satellite or cellular. (Power lines can carry data too, though not well; water and sewer pipes cannot.) Fiber can be in either place. What decides it is not the medium but where the link sits: between providers, or between a provider and one customer.

What you'll learn

Place a connection on the internet backbone, the shared high-capacity lines that join providers' networks, or on the last mile, the link from an ISP to one customer
Name the common last-mile options (DSL over the phone line, cable, fiber, satellite and cellular) and explain why the last mile costs the most per user

Aligned to

CompTIA A+ Core 1

2.7 Compare and contrast Internet connection types, network types, and their features.

CompTIA Tech+

2.4 Compare and contrast common Internet connectivity options.

Cisco CCST Networking

1.3 Differentiate between LAN, WAN, MAN, CAN, PAN, and WLAN

3.2 Differentiate between Wi-Fi, cellular, and wired network technologies

Key terms

Internet Service Provider: A company that provides end users with access to the internet by connecting them to the internet backbone.
Internet Backbone: The high-capacity data routes and core infrastructure that carry aggregated internet traffic between major networks and ISPs.
Last Mile: The final leg of a telecommunications network that connects an ISP to the end user's location, often the most costly segment to deploy.
Digital Subscriber Line: A last-mile connection technology that delivers internet service over existing telephone lines.
Fiber Optic Cable: A high-speed physical transmission medium that uses light signals to carry data over long distances, including undersea routes that interconnect global networks.
Satellite Link: A wireless transmission method that routes data signals to and from orbiting satellites to connect networks across geographic regions, typically with higher latency than cable-based connections.
Cellular Data: A wireless data connection provided through mobile carrier networks, allowing devices to access the internet without Wi-Fi.
Wide Area Network: A network that spans a large geographic area, connecting multiple local area networks.

Topics

Internet Backbone Last Mile Internet Service Provider Interactive Categorize

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