Ethernet network technology is still one of the most popular LAN technologies in use today by many organizations and educational institutions worldwide. The throughput offered by the 10 and 100 Mbps Ethernet is inadequate for supporting high bandwidth applications such as real-time multimedia and Web applications. Gigabit Ethernet (GigE) technology provides 1000 megabits per second (i.e., one gigabit per second) at a more reasonable cost than the other technologies of comparable speed, therefore it is a natural upgrade strategy for many legacy Ethernet networks. This chapter updates our previous research on GigE that has been documented as a case study of a large New Zealand organization. We focused on the level of GigE deployment, design, planning, implementation, network performance testing, problems encountered, and future plans. Our research findings show the feasibility and practicability of deploying GigE technology in high-speed networking applications, such as campus- and corporatewide local area networks.
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.
Gigabit ethernet standards
Figure 2. Top
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.