Alcatel-Lucent 7450 Manual page 34

Label Switching Routers
When an LSP is first established, the bandwidth reserved along its primary path is controlled by
the bandwidth parameter in the config>router>mpls>lsp>primary context, whether or not the
LSP has auto-bandwidth enabled, while the bandwidth reserved along a secondary path is
controlled by the bandwidth parameter in the config>router>mpls>lsp>secondary context.
When auto-bandwidth is enabled and a trigger occurs, the system will attempt to change the
bandwidth of the LSP to a value between min-bandwidth and max-bandwidth, which are
configurable values in the lsp>auto-bandwidth context. min-bandwidth is the minimum
bandwidth that auto-bandwidth can signal for the LSP and max-bandwidth is the maximum
bandwidth that can be signaled. The user can set the min-bandwidth to the same value as the
primary path bandwidth but the system will not enforce this restriction. The system will allow:
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All of the auto-bandwidth adjustments discussed are performed using MBB procedures.
Auto bandwidth can be added to an operational LSP at any time (without the need to shut down the
LSP or path), but no bandwidth change occurs until a future trigger event. Auto bandwidth may
also be removed from an operational LSP at any time and this causes an immediate MBB
bandwidth change to be attempted using the configured primary path bandwidth.
Note that changing the configured bandwidth of an auto-bandwidth LSP has no immediate affect,
it will only matters if the LSP/path goes down (due to failure or administrative action) and comes
back up or if auto-bandwidth is removed from the LSP. The operator can force an auto-bandwidth
LSP to be resized immediately to an arbitrary bandwidth using the appropriate tools commands.
Autobandwidth on LSPs with Secondary or Secondary Standby Paths
Autobandwidth is supported for LSPs that have secondary or secondary standby paths. A
secondary path is only initialized at its configured bandwidth when it is established, and the
bandwidth is adjusted only when the secondary path becomes active.
This description makes use of the following terminology:
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No min-bandwidth to be configured. In this case, the implicit minimum is 0 Mbps
No max-bandwidth to be configured, as long as overflow-triggered auto-bandwidth is not
configured. In this case, the implicit maximum is infinite (effectively 100 Gbps).
The configured primary path bandwidth to be outside the range of min-bandwidth to max-
bandwidth.
auto-bandwidth parameters can be changed at any time on an operational LSP; in most
cases the changes have no immediate impact but subsequent sections will describe some
exceptions
current_BW: the last known reserved bandwidth for the LSP; may be the value of a
different path from the currently active path.
operational BW: the last known reserved BW for a given path, as recorded in the MIB
configured BW: the bandwidth explicitly configured for the LSP path by the user in CLI
7450 ESS MPLS Guide