Author: Neftaly Malatjie

Think of a topology as a network’s virtual shape or structure. This shape does not necessarily correspond to the actual physical layout of the devices on the network. For example, the computers on a home network may be arranged in a circle in a family room, but it would be highly unlikely to find a ring topology there.

Network topologies are categorized into the following basic types:

• bus
• ring
• star
• tree
• mesh

More complex networks can be built as hybrids of two or more of the above basic topologies.

In computer networking, topology refers to the layout of connected devices. This article introduces the standard topologies of networking.

A homogeneous network is a computer network comprised of computers using similar configurations and protocols. A good example of a homogeneous network is a one using Microsoft Windows over TCP/IP.

Homogeneous networks are the simplest networks to administer, but most corporate networks are heterogeneous networks for the following reasons:

• Budgets are limited, so it is not always possible to upgrade an older heterogeneous network into a newer homogeneous one unless the ultimate cost savings can be justified to management.
• Products continually evolve, so what might be a state-of-the-art network operating system today will be a second-class system tomorrow.
• Management and user expectations and needs evolve, so upgrading a second-class system might not be as appropriate as replacing it entirely with something newer.
• Decision making involves politics, and different groups might press for purchasing software that they are more comfortable with instead of making prudent long-term decisions.

A heterogeneous network is a network connecting computers and other devices with different operating systems and/or protocols.

For example, local area networks (LANs) that connect Microsoft Windows and Linux based personal computers with Apple Macintosh computers are heterogeneous.

The word heterogeneous network is also used in wireless networks using different access technologies. For example, a wireless network which provides a service through a wireless LAN and is able to maintain the service when switching to a cellular network is called a wireless heterogeneous network.

Internetworking is the process or technique of connecting different networks by using intermediary devices such as routers or gateway devices. 

Internetworking ensures data communication among networks owned and operated by different entities using a common data communication and the Internet Routing Protocol. The Internet is the largest pool of networks geographically located throughout the world but these networks are interconnected using the same protocol stack, TCP/IP. Internetworking is only possible when the all the connected networks use the same protocol stack or communication methodologies.