Further, Ethernet, true to its historical form, continues to evolve
to make it even more acceptable as an access mechanism. Numerous standards are
emerging to address the specific challenges of delivering Ethernet in the MAN and
WAN; some like the IEEE 802.3ah Ethernet in the First Mile (EFM) have already been
ratified (discussed later in chapter 2). Enterprises are well aware of the evolution of
Ethernet in the LAN and the consequent benefits in terms of price/performance over
the last three decades. They are comfortable that Ethernet in its new role in the MANs
and WANs as well.
Bandwidth Scalability and Flexibility Ethernet LANs commonly operate anywhere from
1M to 1000M, usually tending toward the higher speeds because of the relatively minor
increase45 in the cost of these interfaces and the substantially lowered cost per
bit.(Considering the cost of a 1000M interface is typically about two to three times that
of a 100M port, this means that the cost per bit using a 1000M port instead of a 100M
port would be reduced by 70 percent.46)
Multimedia applications (such as video conferencing and real-time backup) in the
LAN are also bandwidth intensive and are, in fact, requiring higher speed LANs.
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