Automatic Bandwidth Allocation For Lsps; Configuring Automatic Bandwidth Allocation For Lsps - Juniper ACX1000 Configuration Manual

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Automatic Bandwidth Allocation for LSPs

Configuring Automatic Bandwidth Allocation for LSPs

Copyright © 2017, Juniper Networks, Inc.
Pseudowire Overview for ACX Series Universal Access Routers on page 590
Configuring the Pseudowire Status TLV on page 608
Automatic bandwidth allocation allows an MPLS tunnel to automatically adjust its
bandwidth allocation based on the volume of traffic flowing through the tunnel. You can
configure an LSP with minimal bandwidth; this feature can dynamically adjust the LSP's
bandwidth allocation based on current traffic patterns. The bandwidth adjustments do
not interrupt traffic flow through the tunnel.
You set a sampling interval on an LSP configured with automatic bandwidth allocation.
The average bandwidth is monitored during this interval. At the end of the interval, an
attempt is made to signal a new path for the LSP with the bandwidth allocation set to
the maximum average value for the preceding sampling interval. If the new path is
successfully established and the original path is removed, the LSP is switched over to
the new path. If a new path is not created, the LSP continues to use its current path until
the end of the next sampling interval, when another attempt is made to establish a new
path. Note that you can set minimum and maximum bandwidth values for the LSP.
During the automatic bandwidth allocation interval, the router might receive a steady
increase in traffic (increasing bandwidth utilization) on an LSP, potentially causing
congestion or packet loss. To prevent this, you can define a second trigger to prematurely
expire the automatic bandwidth adjustment timer before the end of the current
adjustment interval.
Automatic bandwidth allocation allows an MPLS tunnel to automatically adjust its
bandwidth allocation based on the volume of traffic flowing through the tunnel. You can
configure an LSP with minimal bandwidth, and this feature can dynamically adjust the
LSP's bandwidth allocation based on current traffic patterns. The bandwidth adjustments
do not interrupt traffic flow through the tunnel.
At the end of the automatic bandwidth allocation time interval, the current maximum
average bandwidth usage is compared with the allocated bandwidth for the LSP. If the
LSP needs more bandwidth, an attempt is made to set up a new path where bandwidth
is equal to the current maximum average usage. If the attempt is successful, the LSP's
traffic is routed through the new path and the old path is removed. If the attempt fails,
the LSP continues to use its current path.
NOTE: In calculating the value for
the sample collected during make before break (MBB) is ignored to prevent
inaccurate results. The first sample after a bandwidth adjustment, or after
a change in the LSP ID (regardless of path change), is also ignored.
Chapter 20: Configuring MPLS and Pseudowires
(relative to the ingress LSP),
Max AvgBW
611