Traffic control
Path Computation Element – Bringing the WAN to the SDN era

The PCEP protocol can be used to manipulate LSPs, creating them, modifying their characteristics, etc.

Today, however, the protocol does not control how an LSP is used.

Indeed, while it's important to be able to define paths within the network, it's also essential to be able to direct customer traffic along these paths via routing policies.

The way in which routing policies are used to direct traffic differs greatly from one manufacturer's implementation to another; however, there are certain identical concepts, which we will attempt to describe in a non-exhaustive way.

It's important to understand that the concepts described here are not inherent to PCE, but come from distributed traffic engineering.