Operation Manual – MPLS TE
H3C S9500 Series Routing Switches
Chapter 1 MPLS TE Configuration
1-2
1.1.1 Traffic Engineering and MPLS TE
I. Traffic engineering
Network congestion is one of the major problems that can degrade your network
backbone performance. It may occur either when network resources are inadequate or
when load distribution is unbalanced. Traffic engineering (TE) is intended to avoid the
latter situation where partial congestion may occur as the result of inefficient resource
allocation.
TE can make best utilization of network resources and avoid non-even load distribution
by real-time monitoring traffic and traffic load on each network elements to dynamically
tune traffic management attributes, routing parameters and resources constraints.
The performance objectives associated with TE can be either of the following:
z
Traffic oriented. These are performance objectives that enhance quality of service
(QoS) of traffic streams, such as minimization of packet loss, minimization of delay,
maximization of throughput and enforcement of service level agreement (SLA).
z
Resource oriented. These are performance objectives that optimize resources
utilization. Bandwidth is a crucial resource on networks. Efficiently managing it is
one major task of TE.
1) TE
solution
As existing interior gateway protocols (IGPs) are topology-driven and consider only
network connectivity, they fail to present some dynamic factors such as bandwidth and
traffic characteristics.
This IGP disadvantage can be repaired by using an overlay model, such as IP over
ATM or IP over FR. An overlay model provides a virtual topology above the physical
network topology for a more scalable network design. It also provides better traffic and
resources control support for implementing a variety of traffic engineering policies.
Despite all the benefits, overlay models are not suitable for implementing traffic
engineering in large-sized backbones because of their inadequacy in extensibility. In
this sense, MPLS TE is a better traffic engineering solution for its extensibility and ease
of implementation.
II. MPLS TE
MPLS is better than IGPs in implementing traffic engineering for the following:
z
MPLS supports explicit LSP routing.
z
LSP routing is easy to manage and maintain compared with traditional
packet-by-packet IP forwarding.
z
MPLS TE uses less system resources compared with other traffic engineering
implementations.
MPLS TE combines the MPLS technology and traffic engineering. It delivers these
benefits:
