Fibre Channel SAN Extension over Optical Networks CWDM Concepts
CWDM vs. DWDM
CWDM is:
– More cost-effective than DWDM
– Becoming more interesting for point-to-point applications
– Replacing some DWDM business
– Expanding the scalability of conventional systems
DWDM
CWDM reduces cost
CWDM
4
DWDM allows for capacity growth
18 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.
CWDM is not:
– As scalable as DWDM
– Targeted for distances greater than 120 km
– A solution that will dominate the metro WDM market