Digital Subscriber Line
DSL is one of the most prevalent forms of internet connection. DSL provides high-speed networking over ordinary phone lines using digital modems. DSL connection sharing can be easily achieved with either wired or wireless broadband routers. In some countries, DSL service is also known as ADSL, ADSL2, or ADSL2+.
Cable Modem Internet
Like DSL, a cable modem is a form of broadband internet connection. Cable internet uses neighborhood cable television conduits rather than telephone lines, but the same broadband routers that share DSL internet connections also work with cable. Cable internet is more popular than DSL in the United States, but in some countries, the reverse is true.
Dial-Up Internet
Once the world standard for internet network connections, dial-up has been all but replaced with higher-speed options. Dial-up uses ordinary telephone lines but, unlike DSL, dial-up connections take over the wire, preventing simultaneous voice calls. Most home networks employ Internet Connection Sharing solutions with dial-up internet. Dial-up routers are difficult to find, expensive, and, generally, do not perform well given such a slow internet pipe. Dial-up is most commonly used in lightly populated areas where cable and DSL internet services are unavailable. Travelers and those with unreliable primary internet services also use dial-up as a solid secondary access method.
Integrated Services Digital Network
In the 1990s, ISDN internet served many customers wanting DSL-like service before DSL became widely available. ISDN works over telephone lines and, like DSL, supports simultaneous voice and data traffic. Additionally, ISDN provides two to three times the performance of most dial-up connections. Home networking with ISDN works similarly to networking with dial-up. Due to its relatively high cost and low performance compared to DSL, ISDN is only a practical solution for those looking to squeeze extra performance from their phone lines where DSL is unavailable.
Satellite Internet
Enterprises like Hughes and Viasat offer satellite internet service. With an exterior-mounted mini-dish and a proprietary digital modem inside the home, internet connections can be established over a satellite link similar to satellite television services. Satellite internet can be troublesome to the network. Satellite modems may not work with broadband routers, and some online services like VPNs and online games may not function over satellite connections. Subscribers to satellite internet service generally want the highest available bandwidth in environments where cable and DSL are unavailable.
Broadband Over Power Line
BPL supports internet connections over residential power lines. The technology behind power line BPL works analogously to phone line DSL, using unused signaling space on the wire to transmit the internet traffic. However, BPL is a controversial internet connection method. BPL signals generate interference in the vicinity of power lines, affecting other licensed radio transmissions. BPL requires specialized (but not expensive) equipment to join to a home network. Do not confuse BPL with powerline home networking. Powerline networking establishes a local computer network within the home but does not reach the internet. BPL, on the other hand, reaches to the internet service provider over utility power lines.
Other Forms of Internet Connectivity
Other forms of connectivity are relatively rare, or out-of-date, but still occasionally available for subscription:
Fractional T1/T3 Internet: T1 and T3 are the names telecommunications firms have given to leased line network cables. Installed in some multi-resident dwellings, fractional T1/T3 lines are typically underground fiber or copper cables that connect to the service provider, with individual home connections switched over Ethernet cables. Cellular Internet: Mobile internet over digital cellphones or cellular routers offer good access but most include data caps. Wireless Broadband Internet: WiMAX technology supports high-speed wireless internet using base stations like cellular networks. So-called Wi-Fi community or mesh networks serve a similar function using different technologies.
