Today, that high-speed network usually consists of fiber optic cable and switches that use light waves to transmit data with a connection protocol known as Fibre Channel. (A protocol is a set of rules used by the computer devices to define a common communication language.) More and more, regular Internet provider (IP)-based networks, such as the Internet, are being used as the network part of a SAN.
The act of using a network to create a shared pool of storage devices is what makes a SAN different. The network is used to move data among the various storage devices, allows sharing data between different network servers, and provides a fast connection medium for data backup and restoration and data archiving and retrieval. Devices in a SAN are usually bunched closely together in a single room, but the network allows the devices to be connected over long distances. The ability to spread everything out over long distances makes a SAN very useful to large companies with many offices.
Fiber optic cable is one of the simplest parts of a SAN and one of the most time-consuming to troubleshoot when something goes wrong. It’s better to make sure nothing goes wrong by taking care in the installation and handling of your SAN cabling.
This chapter provides reference material for readers who may be less familiar with either Fiber Channel or IP/Ethernet technology. The following we will introduce the optical cables options in SANs. Next, we will mention LC-LC cables, SC-LC cables, SMF cables.
LC connector are used to attach fiber optic cable to SFPs and patch panels. An LC to LC fiber cable has this connector on each end. It could be used to connect two routers together, to connect a router to a 1Gbit or 2Gbit Fiber Channel device or switch, to a patch panel, or to many Gigabit Ethernet devices. These cables can be purchased in either MMF or SMF versions.
SC connector are used to attach fiber optic cable to GBICs and patch panels. An SC to LC fiber cable has this connector on one end and an LC connector on the other end. It could be used to connect a router to an older Fiber Channel node or switch, to a patch panel, or to many Gigabit Ethernet devices. Some 2Gbit FC devices use and therefor SC connectors as well, and the router would require this cable to connect to them. These cables can be purchased in either MMF or SMF verisons.
Multi-Mode Fiber is used for short distances. It is less expensive than SMF, and is the most common cables type for use inside a datacenter or campus. These cables use a larger diameter (50/125um or 62.5/125um.) fiber core on the inside of the cladding. (Cladding is the sheath around the outside of the fiber.) Most often these cables are used with SWL GBICs and SFPs. Be sure to check that the transeiver is designed to work with the cable diameter (50 or 62.5) since there are two formats. Brocade switches all work equally well with either format, so it should work as long as the transceiver is supported by Brocade and matched to the cable. Usually, MMF cables are orange, but they can ordered in non-standard colors so this is not a totally reliable way to distinguish them from SMF cables. Look for writing on the cable cladding as well.
Single-Mode Fiber can be used for short distances, but due to its greater cost it is almost exclusively use for much longer distance links in combination with LWL, ELWL or WDM solutions. Generall speaking, these soloutions are desinged for SMF cables with media designed for MMF can cause problems. SMF cables use a much smaller diameter fiber core inside the cladding: 9/12um. They are usually colored yellow, but like MMF cables they can be ordered in other colors.
I hope this post was helpful to you when you are choosing optic cable in SANs. If you are interested in requesting a optical cable, please go to the Fiberstore online website.