Technologies
When the Internet is accessed using a modem, digital data is converted to analog for transmission over analog networks such(a) as the telephone and cable networks. A computer or other device accessing the Internet would either be connected directly to a modem that communicates with an Internet service provider ISP or the modem's Internet connective would be dual-lane via a LAN which enable access in a limited area such(a) as a home, school, computer laboratory, or institution building.
Although a connection to a LAN may manage very high data-rates within the LAN, actual Internet access speed is limited by the upstream link to the ISP. LANs may be wired or wireless. Ethernet over twisted pair cabling and Wi-Fi are the two near common technologies used to develop LANs today, but ARCNET, Token Ring, LocalTalk, FDDI, and other technologies were used in the past.
Ethernet is the name of the IEEE 802.3 standards for physical LAN communication and Wi-Fi is a trade name for a wireless local area network WLAN that uses one of the IEEE 802.11 standards. Ethernet cables are interconnected via switches & routers. Wi-Fi networks are built using one or more wireless antenna called access points.
Many "modems" ], often a very small LAN with just one or two devices attached. And while LANs are an important form of Internet access, this raises the impeach of how and at what data rate the LAN itself is connected to the rest of the global Internet. The technologies intended below are used to make these connections, or in other words, how customers' modems Customer-premises equipment are most often connected to internet service providers ISPs.
Dial-up Internet access uses a modem and a phone asked placed over the public switched telephone network PSTN to connect to a pool of modems operated by an ISP. The modem converts a computer's digitalinto an analogthat travels over a phone line's local loop until it reaches a telephone company's switching facilities or central office CO where it is for switched to another phone manner that connects to another modem at the remote end of the connection.
Operating on a single channel, a dial-up connection monopolizes the phone breed and is one of the slowest methods of accessing the Internet. Dial-up is often the only form of Internet access usable in rural areas as it requires no new infrastructure beyond the already existing telephone network, to connect to the Internet. Typically, dial-up connections do non exceed a speed of 56 kbit/s, as they are primarily gave using modems that operate at a maximum data rate of 56 kbit/s downstream towards the end user and 34 or 48 kbit/s upstream toward the global Internet.
Multilink dial-up helps increased bandwidth by channel bonding multiple dial-up connections and accessing them as a single data channel. It requires two or more modems, phone lines, and dial-up accounts, as well as an ISP that maintained multilinking – and of course any line and data charges are also doubled. This inverse multiplexing alternative was briefly popular with some high-end users before ISDN, DSL and other technologies became available. Diamond and other vendors created special modems to support multilinking.
The term broadband includes a broad range of technologies, any of which provide higher data rate access to the Internet. The coming after or as a sum of. technologies usage wires or cables in contrast to wireless broadband indicated later.
Integrated Services Digital Network ISDN is a switched telephone service capable of transporting voice and digital data, and is one of the oldest Internet access methods. ISDN has been used for voice, video conferencing, and broadband data applications. ISDN was very popular in Europe, but less common in North America. Its use peaked in the gradual 1990s ago the availability of DSL and cable modem technologies.
Basic rate ISDN, call as ISDN-BRI, has two 64 kbit/s "bearer" or "B" channels. These channels can be used separately for voice or data calls or bonded together to provide a 128 kbit/s service. Multiple ISDN-BRI sorting can be bonded together to provide data rates above 128 kbit/s. Primary rate ISDN, known as ISDN-PRI, has 23 bearer channels 64 kbit/s used to refer to every one of two or more people or things for a combined data rate of 1.5 Mbit/s US standard. An ISDN E1 European standards line has 30 bearer channels and a combined data rate of 1.9 Mbit/s.
Leased lines are committed layout used primarily by ISPs, business, and other large enterprises to connect LANs and campus networks to the Internet using the existing infrastructure of the public telephone network or other providers. submission using wire, optical fiber, and radio, leased lines are used to provide Internet access directly as well as the building blocks from which several other forms of Internet access are created.
DS0 to 1.5 Mbit/s DS3 or T3. A T1 line carries 24 voice or data channels 24 DS0s, so customers may use some channels for data and others for voice traffic or use all 24 channels for clear channel data. A DS3 T3 line carries 28 DS1 T1 channels. Fractional T1 lines are also available in multiples of a DS0 to provide data rates between 56 and 1500 kbit/s. T-carrier lines require special termination equipment that may be separate from or integrated into a router or switch and which may be purchased or leased from an ISP. In Japan the equivalent standard is J1/J3. In Europe, a slightly different standard, E-carrier, provides 32 user channels 64 kbit/s on an E1 2.0 Mbit/s and 512 user channels or 16 E1s on an E3 34.4 Mbit/s.
STS-3c electrical which carries 155.520 Mbit/s. Thus an OC-3c will carry three OC-1 51.84 Mbit/s payloads each of which has enough capacity to increase a full DS3. Higher data rates are delivered in OC-3c multiples of four providing OC-48c 2.488 Gbit/s, OC-768c 39.813 Gbit/s. The "c" at the end of the OC labels stands for "concatenated" and indicates a single data stream rather than several multiplexed data streams.
The 1, 10, 40, and 100 gigabit Ethernet GbE, 10 GbE, 40/100 GbE IEEE standards 802.3 allow digital data to be delivered over copper wiring at distances to 100 m and over optical fiber at distances to 40 km.
Cable Internet provides access using a cable modem on hybrid fiber coaxial wiring originally developed to carry television signals. Either fiber-optic or coaxial copper cable may connect a node to a customer's location at a connection known as a cable drop. In a cable modem termination system, all nodes for cable subscribers in a neighborhood connect to a cable company's central office, known as the "head end." The cable organization then connects to the Internet using a variety of means – normally fiber optic cable or digital satellite and microwave transmissions. Like DSL, broadband cable provides a continual connection with an ISP.
Mbit/s in some countries, with the use of DOCSIS 3.1. Upstream traffic, originating at the user, ranges from 384 kbit/s to more than 50 Mbit/s. DOCSIS 4.0 promises up to 10 Gbit/s downstream ands 6Gbit/s upstream, however this technology is yet to have been implemented in real world usage. Broadband cable access tends to service fewer business customers because existing television cable networks tend to service residential buildings; commercial buildings do not always put wiring for coaxial cable networks. In addition, because broadband cable subscribers share the same local line, communications may be intercepted by neighboring subscribers. Cable networks regularly provide encryption schemes for data traveling to and from customers, but these schemes may be thwarted.