EXFO FTB-8510B Guia Del Usuario página 1324

Glossary
Next-Gen - Link-Capacity Adjustment Scheme (LCAS)
In addition to providing a resiliency mechanism for VCAT, LCAS gives
service providers the flexibility to tailor service bandwidth as required. For
example, if a certain customer requires additional bandwidth in the late
evenings for file transfers (i.e., banking institutions), the service provider
can provide a value-added service by provisioning increased bandwidth for
a predefined period. Therefore, by dynamically altering the bandwidth of
SONET/SDH transport pipes, LCAS allows network designers to adjust
bandwidth based on quality of service (QoS) or other priority
considerations.
As with VCAT, LCAS is only required at the terminating points of a circuit
and the remainder of the network is oblivious to its presence. In order for
LCAS to operate, two transmission paths in opposite directions must be
established in order to terminate the protocol (see figure below).
Each of these transmission paths link the network elements (NE) located at
each end of the circuit. In the LCAS protocol, one NE is designated as the
Source and one is designated as the Sink. This defines an origination path.
Another source/sink pair, in the opposite direction, must also be created to
serve as a return path. Between two NEs, the LCAS information exchange
always proceeds from the Source (So) to the Sink (Sk). The information is
packaged in a control packet (CTRL) that contains data about the source
members, as well as transferred information from the sink.
674
LCAS Protocol Transmission
FTB-8100 Series Transport Blazer