Internetworking

And in the Cisco Systems 2500 Series router, a small-to-medium enterprise computer internetworking appliance.

Assistive protocols The Internet Protocol is the protocol that defines and enables internetworking at the Internet Layer and thus forms the Internet.

Internetworking is a combination of the words inter ("between") and networking; not internet-working or international-network.

Internetworking is the practice of connecting a computer network with other networks through the use of gateways that provide a common method of routing information packets between the networks.

Internetworking requires sending data from the source network to the destination network.

IP enables internetworking and, in essence, establishes the Internet itself.

It is therefore also referred to as the layer that establishes internetworking, indeed, it defines and establishes the Internet.

Networking models Two architectural models are commonly used to describe the protocols and methods used in internetworking.

Simply using either a switch or a hub to connect two local area networks together doesn't imply internetworking; it just expands the original LAN.

Some of the protocols carried by IP, such as ICMP which is used to transmit diagnostic information, and IGMP which is used to manage IP Multicast data, are layered on top of IP but perform internetworking functions.

The monolithic Transmission Control Program was later divided into a modular architecture consisting of the Transmission Control Protocol at the connection-oriented layer and the Internet Protocol at the internetworking (datagram) layer.

The primary part of XNS is its definition of the Internal Transport layer (layer 1), which corresponds to OSI's Network layer, and it is here that the primary internetworking protocol, IDP, is defined.

Thus, translation facilities must exist for internetworking or nodes must have duplicate networking software for both networks.

With this functionality, the internet layer makes possible internetworking, the interworking of different IP networks, and it essentially establishes the Internet.