Cabling and Test Considerations for 10 Gigabit Ethernet (10 GigE) Local Area Networks

Current communication data rates in local networks range from 10/100 megabits per second (Mbps) in Ethernet to 1 gigabit per second (Gbps) in fiber distributed data interface (FDDI) and Gigabit Ethernet (GigE). However, the increasing demand for internet protocol (IP)-based services including voice, video, and data requires higher speeds and greater bandwidth, leading to the emergence of 10 GigE local area networks (LANs), especially in the enterprise. The 10 GigE is also emerging in storage area network (SAN) applications, including switch-to-switch links for very high-speed connections between switches inside data centers and between buildings.

Today’s network architecture should be built using 10 Gbps technology to ensure that the network is scaleable and allows easy and cost-optimized upgrades.

This white paper should provide an understanding of 10 GigE network complexities, including the difference between multimode and single-mode fiber, limitations and demands associated with 10 GigE LAN environments, and how the complexities can impact future requirements for high-speed networks. It will also review 10 GigE acceptance testing, including a review of test equipment used to qualify current and future local networks.

Two classifications of fiber are used in fiber optic networks: single-mode and multimode. Single-mode fiber has a small core size of 8 to 12 microns (?m) according to international standards and allows light transmission in only one mode, or ray of light. Single-mode fiber can transmit large bandwidth over long distances (10 Gbps, 40 Gbps with proper dispersion compensating components), so it is generally installed in access, metro, and long-haul networks. On the other hand, single-mode fiber requires expensive light sources and alignment devices that can inject light precisely in the small core of singlemode fibers. This makes single-mode network construction sensitive and costly.

Multimode fiber has a much larger core than singlemode (50, 62.5, or higher ?m), allowing light transmission along multiple paths (modes). This kind of propagation generates disturbances called modal dispersion due to the different speed of each mode. Consequently, the signal attenuation (loss in power) is higher, the bandwidth is limited over distance (10 Gbps over 300 meters), and IEEErecommended maximum distances do not exceed 2 kilometers.Multimode fibers are generally installed in premises and enterprise networks. They are much less sensitive to bending constraints than singlemode fibers, and because the large core in multimode causes it to capture light easily, coupling multimode fibers to light sources or other fibers does not require expensive transmitters or connectors, which makes network deployment and maintenance flexible and cheaper than singlemode.

40G Transport Module for T-BERD/MTS-8000 Platforms

T-BERD/MTS-8000 40G Module