Fibre Channel SAN Extension over Optical Networks
CWDM Concepts
CWDM vs. DWDM
CWDM is: CWDM is not:
– More cost-effective than – As scalable as DWDM
DWDM
– Targeted for distances
– Becoming more interesting greater than 120 km
for point-to-point applications
– A solution that will dominate
– Replacing some DWDM the metro WDM market
business
– Expanding the scalability of
conventional systems
DWDM
CWDM reduces cost
CWDM
DWDM allows for
capacity growth
184 Number of wavelengths
If your distance between sites is less than 120km you could use either CWDM
or DWDM. Then you would have to make the decision about what is more
important to you – scalability (choose DWDM) or cost (choose CWDM).
Exam hint:
If a question ever states that dark fibre is available it is going to be guiding you
towards a wave division multiplexed solution.