Computer networking

Computer networking
Name	Computer networking
Inventor	Paul Baran, Donald Davies
Inception	1960s
Related	ARPANET, Ethernet, Internet Protocol Suite

Computer networking. It is the practice of interconnecting multiple computing devices to share resources and exchange data. This field enables the foundational infrastructure of the modern Internet, linking systems from personal computers to global data centers. Its development has been driven by innovations in hardware, standardized protocols, and architectural models, facilitating everything from simple file sharing to complex cloud-based applications.

History and development

The conceptual foundations for computer networking emerged from work at institutions like the RAND Corporation and the National Physical Laboratory (United Kingdom). Key pioneers such as Paul Baran and Donald Davies independently developed the concept of packet switching, a critical alternative to circuit switching used in traditional telephone exchange systems. The first practical wide-area network was the ARPANET, funded by the Advanced Research Projects Agency (ARPA) of the United States Department of Defense, which went online in 1969 linking nodes at the University of California, Los Angeles, the Stanford Research Institute, the University of California, Santa Barbara, and the University of Utah. Subsequent expansion included the development of early protocols like the Network Control Program and the integration of networks such as CYCLADES in France and NPL network in the United Kingdom, leading to the creation of the Internet Protocol Suite (TCP/IP) by researchers including Vint Cerf and Bob Kahn.

Network types and topologies

Networks are categorized by their geographical scope and structural layout. A local area network (LAN) typically connects devices within a limited area like an office building or campus, often using technologies like Ethernet or Wi-Fi. In contrast, a wide area network (WAN) spans large distances, connecting multiple LANs across cities or countries; the Internet is the largest example. Other types include metropolitan area networks (MANs), personal area networks (PANs) like Bluetooth, and storage area networks (SANs). The physical or logical arrangement of these connections defines the network topology, with common designs being the bus network, star network, ring network, mesh networking, and the tree network. The choice of topology impacts factors like cost, performance, and resilience.

Networking hardware and protocols

Physical devices are essential for network operation. These include network interface controllers (NICs), repeaters, Ethernet hubs, network switches, routers, modems, and firewall appliances. Wireless access points enable connectivity for Wi-Fi networks. Communication is governed by protocols—formal rules and standards. The dominant framework is the Internet Protocol Suite, which includes the Transmission Control Protocol (TCP) and the Internet Protocol (IP). Other critical protocols include the User Datagram Protocol (UDP), Dynamic Host Configuration Protocol (DHCP), Domain Name System (DNS), and the Hypertext Transfer Protocol (HTTP). At the data link layer, protocols like Ethernet and Wi-Fi (governed by IEEE 802.11) are prevalent.

Network architecture and models

To manage complexity, networking concepts are often structured using layered architectural models. The most influential is the Open Systems Interconnection model (OSI model), a seven-layer conceptual framework created by the International Organization for Standardization. While primarily a teaching tool, it provides a universal language for discussing network functions. The practically implemented model is the Internet protocol suite, often called TCP/IP, which organizes functions into four abstraction layers: the link layer, internet layer, transport layer, and application layer. These models enable interoperability between products from different vendors like Cisco Systems, Juniper Networks, and Hewlett Packard Enterprise.

Network services and applications

Networks deliver a vast array of services that form the backbone of modern digital life. Fundamental services include the Domain Name System (DNS), which translates domain names to IP addresses, and Dynamic Host Configuration Protocol (DHCP) for automatic IP assignment. Application-layer protocols enable specific functions: Hypertext Transfer Protocol (HTTP) and HTTPS for the World Wide Web, the Simple Mail Transfer Protocol (SMTP) for email, the File Transfer Protocol (FTP) for file sharing, and the Session Initiation Protocol (SIP) for Voice over IP (VoIP) and videotelephony. Modern developments include content delivery via Content Delivery Networks (CDNs) and distributed applications enabled by cloud computing platforms like Amazon Web Services and Microsoft Azure.

Security and management

As networks have grown, so have threats, making security a paramount concern. This involves protecting data and resources from attacks such as malware, denial-of-service attacks, and packet sniffing. Common security measures include firewalls, intrusion detection systems (IDS), virtual private networks (VPNs), and encryption protocols like Transport Layer Security (TLS) and IPsec. Network management encompasses the administration, operation, and maintenance of network resources, often using protocols like the Simple Network Management Protocol (SNMP) and frameworks from organizations like the International Telecommunication Union (ITU) and the Institute of Electrical and Electronics Engineers (IEEE). Effective management ensures performance, reliability, and compliance with policies.

Category:Computer networking Category:Information technology Category:Telecommunications