deploying and managing ip over wdm networks - Index of

3. VPNs deployment.
Management of the IP Network Layer 35
3.2.1.1 MPLS Traffic Engineering Implementation
Traffic engineering is defined as that aspect of network engineering concerned
with the performance optimization of traffic handling in operational networks,
where the main focus of the optimization is to minimize overutilization of
capacity when other capacity is available in the network. Traffic engineering
entails the aspect of network engineering concerned with the design, provisioning,
and tuning of operational networks. It applies business goals, technology
and scientific principles to the measurement, modeling, characterization and
control of traffic, and the application of such knowledge and techniques to
achieve specific service and performance objectives, including the reliable and
timely transport of traffic through the network, the efficient utilization of network
resources, and the planning of network capacity [5].
TE enables the mapping of traffic flows onto an existing physical topology.
It provides a means of controlling the distribution of traffic across all network
links so that they are more evenly utilized. The network planner is allowed
to move traffic flows away from the shortest path calculated by the routing
protocol and onto potentially less congested physical paths. TE is currently the
primary application for MPLS because of the unprecedented growth in demand
for network resources, the mission-critical nature of IP applications, and the
increasingly competitive nature of the service provider marketplace. A successful
TE solution can balance a network’s aggregate traffic load on the various links,
routers, and switches in the network so that none of its individual components is
overutilized or underutilized. This results in a network that is more efficiently
operated and provides more predictable service.
MPLS is well suited to enable TE in large ISP networks for the following
reasons:
• Support for explicit paths allows network administrators to specify the
exact physical path that an LSP takes across the service provider’s
network.
• Per-LSP statistics can be used as input to network planning and analysis
tools to identify bottlenecks and trunk utilization, and to plan for
future expansion.
• Constraint-based routing provides enhanced capabilities that allow
an LSP to meet specific performance requirements before it is
established.
Traffic-engineered LSPs are often referred in the literature as MPLS-TE
tunnels.