Common Internet Service Types | CompTIA IT Fundamentals FC0-U61 | 2.4

In this video you will learn about common internet service types such as fiber optics, cable, DSL, & wireless technologies.

Fiber Optic

Fiber optics is a technology that uses glass (or plastic) threads (fibers) to transmit data.  A fiber optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated onto light waves.  Fiber optics is the fastest type of internet service which is primarily used as a backbone between networks. Fiber optic cable comes in two major types:

  • Single-mode:  Has a thin core (between 8 & 10 microns) designed to carry a single light ray long distances (up to 60km or further).  Single-mode cable uses a laser diode as a light source. Typical uses include cable TV and telephone companies.
  • Multi-mode:  Has a thicker core (62.5 microns) than single-mode cable; carries multiple light rays for short distances (up to 10km).  Multi-mode cable uses an LED light source. Typical uses include local and metropolitan area networks (LANs & MANs).

Fiber optic devices and cables use one of several connector types:

  • SC:  uses square connectors
  • LC:  uses square connectors
  • ST:  uses round connectors
Fiber Optic Cable Connectors

A few other advantages that fiber optics presents is:

  • Fiber optic cables have a much greater bandwidth than metal cables.  This means they can carry more data.
  • Fiber optic cables are less susceptible than metal cables to electromagnetic interference (EMI).
  • Fiber optic cables are much thinner and lighter than metal wires.
  • Data can be transmitted digitally (the natural form for computer data) rather than analogically.
  • Very secure medium data transmission.
  • ONT is at your home, so neighborhood internet usage won’t affect your connection speed.

A few disadvantages of fiber optic cabling are:

  • Difficult to install (made of fragile glass [silica] or plastic fibers)
  • Higher cost than cable or DSL wiring.


Prior to the advent of fiber optics, the fastest internet service available to home and business customers was cable internet.  Cable internet is a form of broadband internet access which uses the same RG6 coaxial cable as a cable television, but adds a device called a cable modem to convert the signal for use by computers and home/business networks.

RG6 Coaxial Cable
Typical Cable Modem

Typical cable internet speeds range from 10Mbps up to 100Mbps, but some operators are now offering 500Mbps and 1000Mbps (1Gbps) speeds by using fiber optic service.  Cable internet pricing varies with the downstream and upstream speed chosen. Symmetrical service (same downstream/upstream speed) is typically offered to business customers.  Most cable ISPs do not have data caps. To determine the actual upstream/downstream speeds your connection achieves with an ISP, use a speed-testing website. Many ISPs provide speed-testing web page links on their customer service pages. Upstream refers to data, page requests, email, and so on being sent from your computer or network to the internet.  Downstream refers to any information being received from the internet. Sending data upstream is called uploading and receiving data is called downloading.

Internet Speed Test

Advantages of cable:

  • “Always-on” connection.
  • Faster than dial-up connections or DSL.

Disadvantages of cable:

  • Speeds are sometimes slower than fiber or depend on how many people in an area are connected at once because the neighborhood shares an ISP backbone (main connection to ISP).
  • Not available in all places.

DSL (Digital Subscriber Line)

DSL is a communications medium used to transfer digital signals over standard telephone lines.  Along with cable internet, DSL is one of the most popular ways ISPs provide broadband internet access.  DSL used by telephone companies to provide internet services at speeds much faster than that allowed by analog (dial-up) internet services while allowing traditional analog telephones and devices such as fax machines to share the same connection.  To make this possible, devices called DSL microfilters are attached between telephones and telephony devices such as answering machines, voicemail, and fax machines to prevent interference with DSL signals.

DSL Internet Setup

Traditional DSL runs over telephone lines originally developed for voice services only, it is far slower than a cable internet connection.  Traditional DSL speeds range from 768Kbps/384Kbps (downstream/upstream) to 6Mbps/768Kbps. Speeds decrease as the distance between the DSL service location and the central switch (central office) providing the DSL connection increases.  Most DSL providers do not have data caps.

DSL advantages:

  • Faster than dial-up connections.
  • Users can connect to the internet and talk on the phone simultaneously (unlike dial-up).

DSL disadvantages:

  • Inconsistent internet connection speeds.
  • Available in limited distances from service provider.
  • Speeds drop the greater the distance from the connection to the internet (also known as the central office or central switch).
  • Slower than cable or fiber connections.


Wireless internet service is a type of internet service that provisions connectivity through wireless means. Wireless internet service for homes & businesses permits locations that are beyond the reach of fiber, cable, or DSL services to connect to the internet.  There are 3 types of wireless categories:

  • Radio Frequency (RF)
  • Satellite
  • Cellular

Radio Frequency

Radio frequency wireless is also known as fixed wireless service.  A fixed wireless ISP (WISP) uses a signal tower to send and receive microwave-frequency radio signals.  Each customer location has a small antenna designed to connect to the wireless ISPs signal tower. The antenna is connected to a wireless modem, which can be connected directly to a PC or to a router for sharing the connection. Most fixed wireless ISPs use multiple towers.  Unlike cellular service, a fixed wireless ISP’s connection to a customer relies on line-of-sight signals.  This is necessary because an RF signal is focused, unlike cellular, which uses an omnidirectional (receive or transmit in all directions) signal.  Consequently, the customer’s antenna is typically mounted on the roof or an antenna tower to permit an unobstructed signal to the nearest tower. The signal from the tower is routed to an RF modem in the house or office.


Satellite internet access is internet access provided through communications satellites. Satellite internet services are often bundled with satellite TV service. Satellite internet service uses oval satellite antennas (very similar in appearance to satellite TV antennas) to connect with geosynchronous communication satellites orbiting over the equator.  These satellites relay internet from ground stations to individual users/viewers via a satellite modem. Satellite modems are proprietary to each satellite service and are usually purchased by the user. Satellite internet services offer pricing based on one or two variables:  data bandwidth allowed per month and downstream (download) speed. Data bandwidth per month ranges from 10-50GB (HughesNet Gen 5) to 35-100GB (Viasat).  Current download speeds vary from 12-50Mbps (Viasat) to 25Mbps (for all of HughesNet’s plans). Satellite internet vendors do have data caps.

Satellite advantages are:

  • No geographic barriers; can reach places where cable or fiber are not available.
  • Faster than dial-up connections.

Satellite disadvantages are:

  • Expensive installation.
  • Equipment costs can be expensive (modem & dish).
  • Unreliable; weather conditions can affect connection.
  • Data caps are common with satellite providers.
  • Slow ping rate unsuitable for gaming, video chat, and VoIP.


Cellular internet service is built into smartphones.  There are two ways for other devices such as tablets and PCs to use cellular internet services:

  • Adding a cellular radio and data plan
  • Connecting to a mobile hotspot

To add cellular service to an Android tablet or iPad, the cellular radio must be factory-installed and a suitable data plan purchased from a mobile carrier.  To enable devices that have only Wi-FI (wireless Ethernet) connection to use cellular internet, connect them to a mobile hotspot. Mobile hotspot devices can be purchased from mobile service providers.  For occasional use, many smartphones can also be turned into mobile hotspots. Cellular internet service isn’t recommended as your only connection because it is slower than most other services.

iPhone Personal Hotspot
Internet Service Comparison