Network
Network:
A computer network is a group of computers that use a set of common communication protocols over digital interconnections to share 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.
The nodes of a computer network may include personal computers, servers, networking hardware, or other specialized or general-purpose hosts. They are identified by hostnames and network addresses. Hostnames serve as memorable labels for the nodes, rarely changed after the initial assignment. Network addresses serve for locating and identifying the nodes by communication protocols such as the Internet Protocol.
Computer networks may be classified by many criteria, including the transmission medium used to carry signals, bandwidth, communications protocols to organize network traffic, the network size, the topology, traffic control mechanism, and organizational intent.
Computer networks support many applications and services, such as access to the World Wide Web, digital video, digital audio, shared use of application and storage servers, printers, and fax machines, and use of email and instant messaging applications.
Different Kind of Network:
1. Personal Area Network (PAN)
The smallest and most basic type of network, a PAN is made up of a wireless modem, a computer or two, phones, printers, tablets, etc., and revolves around one person in one building. These types of networks are typically found in small offices or residences and are managed by one person or organization from a single device.
2. Local Area Network (LAN)
We’re confident that you’ve heard of these types of networks before – LANs are the most frequently discussed networks, one of the most common, one of the most original, and one of the simplest types of networks. LANs connect groups of computers and low-voltage devices together across short distances (within a building or between a group of two or three buildings close to each other) to share information and resources. Enterprises typically manage and maintain LANs.
Using routers, LANs can connect to wide area networks (WANs, explained below) to rapidly and safely transfer data.
3. Wireless Local Area Network (WLAN)
Functioning like a LAN, WLANs make use of wireless network technology, such as Wi-Fi. Typically seen in the same types of applications as LANs, these types of networks don’t require that devices rely on physical cables to connect to the network.
4. Campus Area Network (CAN)
Larger than LANs, but smaller than metropolitan area networks (MANs, explained below), these types of networks are typically seen in universities, large K-12 school districts, or small businesses. They can be spread across several buildings that are fairly close to each other so users can share resources.
5. Metropolitan Area Network (MAN)
These types of networks are larger than LANs but smaller than WANs – and incorporate elements from both types of networks. MAN's span an entire geographic area (typically a town or city, but sometimes a campus). Ownership and maintenance are handled by either a single person or company (a local council, a large company, etc.).
6. Wide Area Network (WAN)
Slightly more complex than a LAN, a WAN connects computers together across longer physical distances. This allows computers and low-voltage devices to be remotely connected to each other over one large network to communicate even when they’re miles apart.
The Internet is the most basic example of a WAN, connecting all computers together around the world. Because of a WAN’s vast reach, it is typically owned and maintained by multiple administrators or the public.
7. Storage-Area Network (SAN)
As a dedicated high-speed network that connects shared pools of storage devices to several servers, these types of networks don’t rely on a LAN or WAN. Instead, they move storage resources away from the network and place them into their own high-performance network. SANs can be accessed in the same fashion as a drive attached to a server. Types of storage-area networks include converged, virtual, and unified SANs.
8. System-Area Network (also known as SAN)
This term is fairly new within the past two decades. It is used to explain a relatively local network that is designed to provide high-speed connection in server-to-server applications (cluster environments), storage area networks (called “SANs” as well), and processor-to-processor applications. The computers connected to a SAN operate as a single system at very high speeds.
9. Passive Optical Local Area Network (POLAN)
As an alternative to traditional switch-based Ethernet LANs, POLAN technology can be integrated into structured cabling to overcome concerns about supporting traditional Ethernet protocols and network applications such as PoE (Power over Ethernet). A point-to-multipoint LAN architecture, POLAN uses optical splitters to split an optical signal from one strand of single-mode optical fiber into multiple signals to serve users and devices.
10. Enterprise Private Network (EPN)
These types of networks are built and owned by businesses that want to securely connect their various locations to share computer resources.
11. Virtual Private Network (VPN)
By extending a private network across the Internet, a VPN lets its users send and receive data as if their devices were connected to the private network – even if they’re not. Through a virtual point-to-point connection, users can access a private network remotely.
If you have questions about which type of network is right for your organization or want to learn more about Belden’s network solutions that improve uptime, maintain security, and help improve user access.
History of network:
| 1961 | The idea of ARPANET, one of the earliest computer networks, was proposed by Leonard Kleinrock in 1961, in his paper titled "Information Flow in Large Communication Nets." |
| 1965 | The term "packet" was coined by Donald Davies in 1965, to describe data sent between computers over a network. |
| 1969 | ARPANET was one of the first computer networks to use packet switching. Development of ARPANET started in 1966, and the first two nodes, UCLA and SRI (Standford Research Institute) were connected, officially starting ARPANET in 1969. |
| 1969 | The first RFC surfaced in April 1969, as a document to define and provide information about computer communications, network protocols, and procedures. |
| 1969 | The first network switch and IMP (Interface Message Processor) was sent to UCLA on August 29, 1969. It was used to send the first data transmission on ARPANET. |
| 1969 | The Internet was officially born, with the first data transmission being sent between UCLA and SRI on October 29, 1969, at 10:30 p.m. |
| 1970 | Steve Crocker and a team at UCLA released NCP (NetWare Core Protocol) in 1970. NCP is a file-sharing protocol for use with NetWare. |
| 1971 | Ray Tomlinson sent the first e-mail in 1971. |
| 1971 | ALOHAnet, a UHF wireless packet network, is used in Hawaii to connect the islands together. Although it is not Wi-Fi, it helps lay the foundation for Wi-Fi. |
| 1973 | Ethernet is developed by Robert Metcalfe in 1973 while working at Xerox PARC. |
| 1973 | The first international network connection, called SATNET, is deployed in 1973 by ARPA. |
| 1973 | An experimental VoIP call was made in 1973, officially introducing VoIP technology and capabilities. However, the first software allowing users to make VoIP calls was not available until 1995. |
| 1974 | The first routers were used at Xerox in 1974. However, these first routers were not considered true IP routers. |
| 1976 | Ginny Strazisar developed the first true IP router, originally called a gateway, in 1976. |
| 1978 | Bob Kahn invented the TCP/IP protocol for networks and developed it, with help from Vint Cerf, in 1978. |
| 1981 | Internet Protocol version 4, or IPv4, was officially defined in RFC 791 in 1981. IPv4 was the first major version of the Internet protocol. |
| 1981 | BITNET was created in 1981 as a network between IBM mainframe systems in the United States. |
| 1981 | CSNET (Computer Science Network) was developed by the U.S. National Science Foundation in 1981. |
| 1983 | ARPANET finished the transition to using TCP/IP in 1983. |
| 1983 | Paul Mockapetris and Jon Postel implemented the first DNS in 1983. |
| 1986 | The NSFNET (National Science Foundation Network) came online in 1986. It was a backbone for ARPANET, before eventually replacing ARPANET in the early 1990s. |
| 1986 | BITNET II was created in 1986 to address bandwidth issues with the original BITNET. |
| 1988 | The first T1 backbone was added to ARPANET in 1988. |
| 1988 | WaveLAN network technology, the official precursor to Wi-Fi, was introduced to the market by AT&T, Lucent, and NCR in 1988. |
| 1988 | Details about network firewall technology were first published in 1988. The published paper discussed the first firewall, called a packet filter firewall, that was developed by Digital Equipment Corporation the same year. |
| 1990 | Kalpana, a U.S. network hardware company, developed and introduced the first network switch in 1990. |
| 1996 | IPv6 was introduced in 1996 as an improvement over IPv4, including a wider range of IP addresses, improved routing, and embedded encryption. |
| 1997 | The first version of the 802.11 standards for Wi-Fi is introduced in June 1997, providing transmission speeds up to 2 Mbps. |
| 1999 | The 802.11a standard for Wi-Fi was made official in 1999, designed to use the 5 GHz band and provide transmission speeds up to 25 Mbps. |
| 1999 | 802.11b devices were available to the public starting mid-1999, providing transmission speeds up to 11 Mbps. |
| 1999 | The WEP encryption protocol for Wi-Fi is introduced in September 1999, for use with 802.11b. |
| 2003 | 802.11g devices were available to the public starting in January 2003, providing transmission speeds up to 20 Mbps. |
| 2003 | The WPA encryption protocol for Wi-Fi is introduced in 2003, for use with 802.11g. |
| 2003 | The WPA2 encryption protocol is introduced in 2004, as an improvement over and replacement for WPA. All Wi-Fi devices are required to be WPA2 certified by 2006. |
| 2009 | The 802.11n standard for Wi-Fi was made official in 2009. It provides higher transfer speeds over 802.11a and 802.11g, and it can operate on the 2.4 GHz and 5 GHz bandwidths. |
| 2018 | The Wi-Fi Alliance introduced WPA3 encryption for Wi-Fi in January 2018, which includes security enhancements over WPA2. Modern Communication Tools:
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