Starting Admission Control; Admission Control Interface Table; Configuring Traffic-Engineering Resources - Juniper BGP - CONFIGURATION GUIDE V 11.1.X Configuration Manual

Currently, bandwidth (BW) and bandwidth-related information are the only resources
tracked and used for traffic engineering. Admission control determines whether a
setup request can be honored for an MPLS LSP with traffic parameters.
Admission control provides bandwidth information to the IGP protocols, ISIS and
OSPF. As new LSPs are created, the available bandwidth decreases. The IGPs can
subsequently advertise this information and use it for SPF calculations to determine
paths that satisfy the traffic requirements. You can configure readvertisement to
occur periodically or when the change crosses some threshold.

Starting Admission Control

Admission control operates on a router-wide basis rather than a per-virtual-router
basis. Admission control of resources begins when either of the following occurs:
You configure resource-related information about an interface, including
bandwidth (either total bandwidth or MPLS reservable bandwidth), flooding
frequency, flooding threshold, administrative weight, or attribute flags.
MPLS begins to use admission control services; for example, by attempting to
set up a constraint-based LSP.

Admission Control Interface Table

Configuring bandwidth on an interface creates an entry for the interface in the
admission control interface table. Each entry in the table stores the following
information per interface:
Maximum (physical or line-rate) bandwidth
Maximum reservable bandwidth
The following information per IP class (currently a single, default class)
Total available (unreserved) bandwidth
Available bandwidth at each MPLS priority level
Resource flooding threshold and period
The resource flooding threshold and period together control the flooding of the
resource information by the IGP protocols, IS-IS and OSPF.

Configuring Traffic-Engineering Resources

You can configure the following resource-related information about an MPLS interface
(at either the major interface or subinterface level):
Bandwidth Total bandwidth that can be reserved on the interface
Flooding thresholds Sets of absolute percentages of total reservable bandwidth
that trigger the new bandwidth value to be flooded throughout the network;
flooding is triggered when bandwidth increases past any up threshold value or
decreases past any down threshold value
Chapter 2: MPLS Overview
MPLS Traffic Engineering
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