Types of Data Link for Storage and Networking

Fibre Channel technology lets you increase the distance between the components in a Serviceguard cluster, thus making it possible to design a disaster tolerant architecture. The following table shows some of the distances possible with a few of the available technologies, including some of the Fibre Channel alternatives.

The development of DWDM technology allows designers to use dark fiber (high speed communication lines provided by common carriers) to extend the distances that were formerly subject to limits imposed by Fibre Channel for storage and Ethernet for network links.

WDM stands for Wavelength Division Multiplexing. There are two WDM technology solutions: CWDM (Coarse Wavelength Division Multiplexing) and DWDM (Dense Wavelength Division Multiplexing). CWDM is similar to DWDM but is less expensive, has fewer channels, is less expandable, and works over a distance of 100 km

	NOTE: * DWDM and CWDM can be used beyond the 100 KM limit, however this is the maximum supported distance for Extended Distance Clusters.

	NOTE: Increased distance often means increased cost and reduced speed of connection. Not all combinations of links are supported in all cluster types.