Updating on Gigabit Ethernet Implementation: The Case of a Large New Zealand Organization

Overview Of Gigabit Ethernet

GigE supports four different physical layer implementations, three to which are defined in the IEEE 802.3z standard (802.3, 1998). The fourth is defined in the IEEE 802.3ab standard (802.3ab, 1999). IEEE 802.3z provides the specifications for the 1000BASE-LX, 1000BASE-SX, and 1000BASE-CX physical layers which, together, are generally referred to as 1000BASE-X. 1000BASE-LX networks support three types of optical fibre and 1000BASE-SX networks support two types. 1000BASE-LX can operate over a pair of 10 µm (core diameter) single mode fibres, or 50 or 62.5 µm multimode fibres, and uses long-wavelength (1300 nm nominal) lasers.

An overview of various GigE standards is presented in Figure 1. The frame format of a typical GigE is shown in Figure 2.

Figure 1.

Gigabit ethernet standards

Figure 2.

Gigabit Ethernet frame format

Gigabit Ethernet Deployment Considerations

The three important factors (Intel Corporation, 2003b; Janowski, 2003; Serenbetz, 1998) that are necessary for the proper deployment of GigE are: (1) transmission media selection; (2) testing existing cabling; and (3) identifying potential bottlenecks.