Internet Connections & Network Types | CompTIA A+ 220-1001 | 2.7

In this video you will learn about various internet connection & network types along with their features.

Comparison of Network Connection Speeds (Fastest to Slowest)

  • Wired: Fiber, Cable, DSL, ISDN, Dial-Up
  • Wireless: Cellular, Fixed Line-of-Sight, Satellite

Cable

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 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

The two major types of DSL that use telephone lines are: ADSL (Asynchronous DSL) & SDSL (Synchronous DSL). The two newer types of DSL are: VDSL (Very High Bit-Rate DSL) and VDSL2 (uses fiber for at least part of the signal path). Both VDSL and VDSL2 use fiber for most of the distance from the telephone company’s central office (where all DSL services connect to the internet). SDSL gets its name from providing the same speed in both directions; ADSL is always faster downstream than upstream.

Common DSL Services Compared

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.

Dial-Up

Dial-up internet access is a form of internet access that uses the facilities of the public switched telephone network (PTSN) to establish a connection to an ISP by dialing a telephone number on a conventional telephone line. Dial-up connections use modems to decode audio signals into data to send to a router or computer, and to encode signals from the latter two devices to send to another modem. Until the late 1990s, dial-up networking was the most common way for home & small businesses to connect to the internet. Today, dial-up connections are used when no other internet connection is available. Dial-up has rates ranging from 28.8Kbps to 56Kbps and is available anyplace that has a landline telephone system. A disadvantage of telephone dial-up is that voice and data cannot share the wire simultaneously.

Fiber

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.
  • Optical Network Terminal (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.

Satellite

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.

ISDN

Integrated Services Digital Network is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the traditional circuits of the public switched telephone network. ISDN is used on PSTN lines with a terminal adapter (TA) on multiple channels of 64Kbps each. A TA resembles a conventional analog modem. Internal models plug into the same PCIe or PCI slot used by analog modems, and external models are USB or serial ports.

There are two types of ISDN connections provided by local telephone companies in which both types of connections enable the use of the internet, talk or fax communications through a phone line at the same time:

  • Primary Rate Interface (PRI):  A PRI connection provides 1.536Mbps of bandwidth, whereas a BRI interface provides 64Kbps (single-channel or 128Kbps dual-channel) of bandwidth.  PRI is sold to large organizations.
  • Basic Rate Interface (BRI):  BRI was sold to small businesses and home offices before DSL and cable became widely available.  BRI offers up to 128Kbps of bandwidth.

Most telephone companies have largely phased out ISDN in favor of DSL, which is much faster and less expensive for internet connections.

Cellular

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

Wireless/Cellular Data Network

WiFi connectivity is enabled the same way on a smartphone or tablet as with laptops or other types of computers.  In addition, smartphones or tablets with cellular radios can also be used to share their connections with others.

Tethering

Tethering, or phone-as-modem (PAM), is the sharing of a mobile device’s internet connection with other connected computers. Connection of a mobile device with other devices can be done over wireless LAN (WiFi), over Bluetooth or by a physical connection using a cable, such as a USB.

Hotspots

WiFi hotspots are internet access points that allow you to connect to a WiFi network using your computer, smartphone or another device while away from your home or office network. Be aware that some cellular providers charge additional fees if you turn your cellular device into a hotspot or if you use tethering.  Also keep in mind that the data usage of every device connected to a mobile hotspot is counted toward your total data allocation, which could potentially result in you paying extra money for overages.

Line-of-Sight Wireless

Line-of-sight (LoS, sometimes referred to as terrestrial wireless) is a type of propagation that can transmit and receive data only where transmit and receive stations are in view of each other without any sort of an obstacle between them. This means that the customer antenna must be placed on the roof or on its own stand, and trees may need to be trimmed to provide adequate signal quality. FM radio, microwave and satellite transmission are examples of LoS communication. To bring the network signal into the premises, coaxial cable connects from the antenna to a line-of-sight wireless modem, which is similar to a cable modem.  Connect the modem to a router to provide internet access to multiple devices.  Typical download speeds range from 256Kbps up to 10Mbps.

Network Types

A network is a group of computers that use a set of common communication protocols over digital interconnections for the purpose of sharing resources located on or provided by the network nodes. The interconnections between nodes are formed from a broad spectrum of telecommunication network technologies, based on physically wired, optical, and wireless radio-frequency methods that may be arranged in a variety of network topologies.

LAN

A local area network (LAN) is a computer network within a small geographical area such as a home, school, computer laboratory, office building or group of buildings.  A LAN is composed of interconnected workstations and personal computers which are each capable of accessing and sharing data and devices, such as printers, scanners and data storage devices, anywhere on the LAN.  LANs are characterized by higher communication and data transfer rates and the lack of any need for leased communication lines. LANs can be wired or wireless LANs (WLANs).  Wired LAN can have high-speed connections with Ethernet unshielded twisted pair cable (UTP), shielded twisted pair cable (STP), or fiber.  Legacy LANs were often connected by coax cables.

WAN

A wide area network (WAN) is a network that exists over a large-scale geographical area.  A WAN connects different smaller networks, including LANs and metro area networks (MANs). This ensures that computers and users in one location can communicate with computers and users in other locations.  WAN implementation can be done either with the help of the public transmission system or a private network. The internet is an example of a WAN. WANs are administered by several different internet service providers (ISPs), and the links are usually slower than LAN connections.

PAN

A personal area network is a computer network for interconnecting electronic devices centered on an individual person’s workspace. A PAN provides data transmission among devices such as computers, smartphones, tablets and personal digital assistants. PANs can be used for communication among the personal devices themselves, or for connecting to a higher level network and the internet where one master device takes up the role as gateway. Examples of devices in a PAN are wireless headsets, keyboards, mice, printers, and bar code readers. A PAN may be wireless or carried over wired interfaces such as USB.

MAN

A metropolitan area network is a computer network that interconnects users with computer resources in a geographic region of the size of a metropolitan area. The term MAN is applied to the interconnection of LANs in a city into a single larger network which may then also offer efficient connection to a WAN. The term is also used to describe the interconnection of several LANs in a metropolitan area through the use of point-to-point connections between them.

WMN

A wireless mesh network is a communications network made up of radio nodes organized in a mesh topology. It can also be a form of wireless ad hoc network. WMNs often consist of mesh clients, mesh routers and gateways. WMNs can range from very small home networks to large city-wide networks. Management of a WMN is decentralized.  Without a central connection device, it can take time for all the wireless devices to find each other if they are moving around.