H3C Technologies H3C S6800 Series Switches - Manual (Page 66)

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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 the following:
• Real-time monitoring of traffic and traffic load on network elements.
• 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.
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, and specify constrains, such as the bandwidth and explicit paths.
• 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 need to 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 on each hop 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 ."
Dynamic CRLSP establishment
Dynamic CRLSPs are dynamically established as follows:
1. An IGP advertises TE attributes for links.