| Internetworking | | | | area networks via some sort of wide area |
| Internetworking involves connecting two or more | | | | network. The definition now includes the |
| computer networks via gateways using a | | | | connection of other types of computer networks |
| common routing technology. The result is called an | | | | such as personal area networks.protocol, such as |
| internetwork (often shortened to internet). | | | | The Internet Protocol is designed to provide an |
| The most notable example of internetworking is | | | | unreliable (i.e., not guaranteed) packet service |
| the Internet (capitalized), a network of networks | | | | across the network. The architecture avoids |
| based on many underlying hardware technologies, | | | | intermediate network elements maintaining any |
| but unified by an internetworking protocol | | | | state of the network. Instead, this function is |
| standard, the Internet Protocol Suite (TCP/IP). | | | | assigned to the endpoints of each communication |
| The network elements used to connect individual | | | | session. To transfer data reliably, applications must |
| networks are known as routers, but were | | | | utilize an appropriate Transport LayerTransmission |
| originally called gateways, a term that was | | | | Control Protocol (TCP), which provides a reliable |
| deprecated in this context, due to confusion with | | | | stream. Some applications use a simpler, |
| functionally different devices using the same | | | | connection-less transport protocol, User Datagram |
| name. | | | | Protocol (UDP), for tasks which do not require |
| The interconnection of networks with bridges (link | | | | reliable delivery of data or that require real-time |
| layer devices) is sometimes incorrectly termed | | | | service, such as video streaming |
| "internetworking", but the resulting system is | | | | Networking models |
| simply a larger, single subnetwork, and no | | | | Two architectural models are commonly used to |
| internetworking protocol (such as IP) is required to | | | | describe the protocols and methods used in |
| traverse it. However, a single computer network | | | | internetworking. The Open System |
| may be converted into an internetwork by | | | | Interconnection (OSI) reference model was |
| dividing the network into segments and then | | | | developed under the auspices of the International |
| adding routers between the segments. | | | | Organization for Standardization (ISO) and |
| The original term for an internetwork was | | | | provides a rigorous description for layering |
| catenet. Internetworking started as a way to | | | | protocol functions from the underlying hardware |
| connect disparate types of networking | | | | to the software interface concepts in user |
| technology, but it became widespread through the | | | | applications. Internetworking is implemented in |
| developing need to connect two or more local | | | | Layer 3 (Network Layer) of the model. |