GMPLS Doubt

Hi,
I am aware that this is a MPLS mailing list but since i could not get this 
doubt clarified
from any other place .. 

This is in reference to "Challenges for MPLS in Optical Network Restoration" by 
Robert
Doverspike and Jennifer Yates which appeared in IEEE Communications Magazine 
(Feb 2001)

The authors say that an "Optical transport system (OTS) multiplexes multiple 
optical signals
onto a common fiber, necessitating the concept of a channel. An optical network 
connection is
provisioned by cross connecting channels within individual OTSs along its path. 
This fact
implies that zero-bandwidth paths cannot be established for later use. In 
contrast, in IP
networks MPLS LSPs may be established such that if no packets  are switched 
into the links
along the path, no bandwidth is consumed. Switching packets onto these 
predefined paths at
their endpoints is simple and rapid. This important difference between IP and 
optical networks
becomes crucial in allocating restoration capacity"

Can somebody help me understand the above?

regards,
mareline s.


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