HP Intelligent Management Center Licenses - Manual (Page 98)

4 MPLS TE manager
Welcome to use this MPLS TE manager help, through which you can know about the functions
provided by the MPLS TE manager and how to use these functions.
Manager overview
Functions of MPLS TE
Network congestion is one of the major problems that can degrade network performance. It may
occur when network resources are inadequate or when load distribution is unbalanced. Traffic
Engineering (TE) is intended to avoid the latter situation, that is, congestion caused by load
imbalance. The existing IGP protocols are all protocol-driven. As they consider only network
connection status, they cannot reflect bandwidth usage status and traffic characteristics. MPLS TE
remedies this IGP disadvantage, and for a large-scale backbone network, it is an excellent TE
solution for its great extensibility and ease of implementation. MPLS TE is a technology combining
traffic engineering and MPLS. Through MPLS TE, a service provider can precisely control data
transmission paths to avoid congestion nodes. In this way, the service provider can solve the
problem that some paths are overloaded while some paths are idle, so as to use the bandwidth
more sufficiently. MPLS TE can also reserve resources during the LSP tunnel establishment to ensure
service quality. Besides, MPLS TE introduces the path backup and Fast Reroute (FRR) mechanisms,
so that it can switch traffic to another path when the current link encounters a problem. To sum up,
through MPLS TE, a service provider can use the existing network resources more sufficiently,
provide diversified services, and optimize network resource allocation.
Basic Concepts of MPLS TE
MPLS TE tunnel: Reroute and transmission over multiple paths may involve multiple LSP tunnels. A
set of such LSP tunnels is called a traffic engineered tunnel (TE tunnel).
Implementation of MPLS TE
The MPLS TE working process mainly involves four steps:
1. Advertising link state information.
Traditional networks perform routing based on only cost values, while MPLS TE performs
routing based on cost values as well as traffic information, bandwidth, and delay parameters,
which are added to the link state information by extending the current link state-based IGPs
such as OSPF and IS-IS. Therefore, the first step to implement MPLS TE is advertising the link
state information to all nodes through the OSPF or IS-IS extension.
2. Calculating paths.
After each node learns the state information of all links on the network, a tunnel's headend
node calculates the shortest path to the tunnel's tailend node. When calculating the shortest
98 MPLS TE manager