Currently, most transport wavelength-division
multiplexing (WDM) networks operate statically
(i.e., lightpaths are established semi-permanently).
Although the high capacity of these lightpaths
is underutilized (10–25 percent [1]), the ever
increasing Internet traffic (annual growing rates
of 35–50 percent [1]) and the emerging worldwide
deployment of fiber to the x (FTTx) can mean
that such high capacity might not be enough to
meet the quality of service requirements of massive
multimedia applications. Facing capacity
exhaustion, network operators will require an
evaluation methodology that allows them to select
the most suitable migration alternative. In this
article, we propose such a methodology, using the
migration cost as the determining selection aspect.