Gigabit Ethernet - The Evolution Of LAN To GigE Standards

It is interesting how the supply and demand for bandwidth has been shaping the evolution of local area networks. Initially, the networks were created to interconnect computers, then applications are introduced that allow these computers to talk. As the applications mature, the network itself becomes a bottleneck. Now a new standard is required to match the demands of the applications. It is this cycle that led to the standardization of GigE.

The local area networks of LANs initially were designed to run on Ethernet as the layer 2. The first Ethernet networks were based on coaxial cables and supported lower bandwidths of 2 to 5 Mbps. The 10 BASE T technologies really changed the LAN networks forever. With the new concepts of unshielded twisted pair or UTP and hubs, the general layout of LANs was transformed.

10 BASE T really made LANs as common and easy to install as they are today. With more computers connected, there was obvious need for better bandwidths. The 10 BASE T addressed this with the 10 Mbps bandwidth. Later the concept of switches was introduced which changed the LAN communications from half duplex to full duplex, literally doubling the LAN capacity. However, these incremental improvements were faster being nullified by the huge leap in applications running on these networks. There was a growing demand for something drastic.

The next drastic evolution can in the form of 100 BASE T standard or the Fast Ethernet. This increased the LAN bandwidth by ten times while retaining all the other improvements from the 10 BASE T standards. This really was a big leap as all of a sudden the entire LAN network got ten times more capacity over the same infrastructure.

With Fast Ethernet becoming an instant success, many people started believing that this would be the last step in the existing LAN infrastructure. Any higher rates like 1 Gbps would have to run on fibre. Copper was not the ideal medium to support 1 Gbps. This was believed to be true till 1999 when the 803.2ab standards were published.

The 802.3ab was significant in many different ways. To start with it showed that copper could support 1 Gbps. Secondly, it used the very same infrastructure that its predecessors the 10 BASE T and the 100 BASE T used. So the physical layout on which most enterprises invested so much money could still be used for future applications too. Of course, it was not a simple upgrade as the Fast Ethernet was; new concepts like auto negotiation had to be incorporated for GigE.

In summary, the modern day LANs have evolved a lot over the decades. While the Fast Ethernet is more or less the norm today, pretty soon, GigE could become commonplace. LANs have evolved right up to GigE stage today which is just amazing considering that the first LANs were just around 2 Mbps.