Traffic Engineering with MPLS

Signaling protocols are used within a Multiprotocol Label Switching (MPLS) environment to establish label-switched paths (LSPs) for traffic across a transit network.

You can use either the J-Web configuration editor or CLI configuration editor to configure signaling protocols.

For more information about MPLS traffic engineering, see the Junos MPLS Applications Configuration Guide.

For information about which devices support the features documented in this chapter, see the Junos OS Feature Support Reference for SRX Series and J Series Devices.

Traffic engineering facilitates efficient and reliable network operations while simultaneously optimizing network resources and traffic performance. Traffic engineering provides the ability to move traffic flow away from the shortest path selected by the interior gateway protocol (IGP) to a potentially less congested physical path across a network. To support traffic engineering, besides source routing, the network must do the following:

• Compute a path at the source by taking into account all the constraints, such as bandwidth and administrative requirements.
• Distribute the information about network topology and link attributes throughout the network once the path is computed.
• Reserve network resources and modify link attributes.

MPLS traffic engineering uses the following components:

• MPLS LSPs for packet forwarding
• IGP extensions for distributing information about the network topology and link attributes
• CSPF for path computation and path selection
• RSVP extensions to establish the forwarding state along the path and reserve resources along the path

J Series devices also support traffic engineering across different OSPF regions. For more details, see the Junos MPLS Applications Configuration Guide.