It is important to note that traffic engineering does not necessarily select the shortest path between two devices. It is possible that, for two packet data flows, the packets may traverse completely different paths even though their originating node and the final destination node are the same. In MPLS, traffic engineering is inherently provided using explicitly routed paths. The LSPs are created independently, specifying different paths that are based on user-defined policies. However, this may require extensive operator intervention.
Explicit hops dictate which path is to be taken.
QoS requirements dictate which links and queuing or scheduling mechanisms are to be employed for the flow. CR can be used in conjunction with MPLS to set up LSPs. Traditional Routing and Packet Switching 3. MPLS and Its Components 4. MPLS Operation 5.