H3C Technologies H3C S12500-X Series Switches - Manual (Page 55)

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Configuring MPLS TE
Overview
TE and MPLS TE
Network congestion can degrade the network backbone performance. It might occur when network
resources are inadequate or when load distribution is unbalanced. Traffic engineering (TE) is intended to
avoid the latter situation where partial congestion might occur because of improper resource allocation.
TE can make the best use of network resources and avoid uneven load distribution by real-time
monitoring of traffic and traffic load on network elements and dynamic tuning of traffic management
attributes, routing parameters, and resources constraints.
MPLS TE combines the MPLS technology and traffic engineering. It reserves resources by establishing LSP
tunnels along the specified paths, allowing traffic to bypass congested nodes to achieve appropriate
load distribution.
MPLS TE features simplicity and good scalability. With MPLS TE, a service provider can deploy traffic
engineering on the existing MPLS backbone to provide various services and optimize network resources
management.
MPLS TE basic concepts
• CRLSP—Constraint-based Routed Label Switched Path. To establish a CRLSP, you must configure
routing (as you do for a normal LSP), and specify constrains, such as the bandwidth.
• MPLS TE tunnel—A virtual point-to-point connection from the ingress node to the egress node.
Typically, an MPLS TE tunnel consists of one CRLSP. To deploy CRLSP backup or transmit traffic over
multiple paths, you must establish multiple CRLSPs for one class of traffic. In this case, an MPLS TE
tunnel consists of a set of CRLSPs. An MPLS TE tunnel is identified by an MPLS TE tunnel interface on
the ingress node. When the outgoing interface of a traffic flow is an MPLS TE tunnel interface, the
traffic flow is forwarded through the CRLSP of the MPLS TE tunnel.
Static CRLSP establishment
A static CRLSP is established by manually specifying the incoming label, outgoing label, and other
constraints (such as bandwidth) on each hop (including the ingress, transit, and egress nodes) along the
path that the traffic travels. Static CRLSPs feature simple configuration, but they cannot automatically
adapt to network changes.
For more information about static CRLSPs, see "Configuring a static CRLSP."