Appendix C: Acronyms
633
(continued)
VCSEL
Vertical-cavity surface-emitting laser
VECP
Vertical eye-closure penalty
VFL
Visual fault locator
VOA
Variable optical attenuator
VSB
Vestigial-sideband
WAN
Wide area network
WDM
Wavelength-division multiplexing
WRN
Wavelength routed network
WSS
Wavelength-selective switch
XPM
Cross-phase modulation
YIG
Yttrium iron garnet