
Evolving SAN, GbE/10GbE, and Metro Ethernet Technologies ◾ 291
difference, for the purists). Channel-level communication is applicable to a number of instances
(e.g., real-time mirroring), but the recent focus has been on connecting storage devices. Hence,
for all intents and purposes, SANs and channel-based communication are thought, of late, as one
and the same. (is author wrote what is regarded as the first textbook treatment of WAN-based
channel extension technologies, with extensive materials on this topic in the 1991 book Telecom-
munications Technology Handbook, Artech House.) In recent years a variety of switches and routers
have been ...