Understanding and Designing Serviceguard Disaster Tolerant Architectures Fourth Edition, December 2007 (T1906-90023)

Building an Extended Distance Cluster Using Serviceguard
Types of Data Link for Storage and Networking
Chapter 266
Types of Data Link for Storage and
Networking
FibreChannel 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 FibreChannel 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
FibreChannel for storage and Ethernet for network links.
NOTE * FDDI Networking is a ring topology therefore, the maximum effective
distance supported between data centers is 50 kilometers.
Table 2-1 Link Technologies and Distances
Type of Link
Maximum Distance
Supported
Fast/Wide SCSI 25 meters
Gigabit Ethernet Twisted Pair 50 meters
Short Wave FibreChannel 500 meters
FDDI Networking 100 kilometers *
Long Wave FibreChannel 10 kilometers
Finisar Gigabit Interface Converters
(GBICs)
80 kilometers
Dense Wave Division Multiplexing
(DWDM)
100 kilometers