4
MPLS label distribution Migrations
MPLS has revolutionized the internetworking industry in recent years. Originally envisioned as a flexible tag-switching architecture that could span beyond an ATM or Frame Relay cloud, MPLS currently constitutes a reference framework to deploy multiple services from optical and Ethernet backhaul to Traffic Engineering or private Layer 3 VPNs.
Multiple enterprises and service providers have had to deploy MPLS in their networks as a moving-forward strategy to better traffic-engineer their networks or offer MPLS-based services, and soon thereafter the question about merging MPLS label distribution domains arose. Different label distribution protocols or even diverse adoptions from an early standard have caused integration headaches for many network engineers.
4.1 Motivations for MPLS label distribution Migrations
Foundations for successful deployment of MPLS-based applications have not only been integrating MPLS with other protocols such as an IGP or BGP, but also the election of the correct strategy for MPLS label allocation and distribution. Those topics have been addressed since the very early origins of MPLS.
[RFC3035], [RFC3036] (made obsolete by [RFC5036]), and [RFC3037] soon advocated the concept of a brand new Label Distribution Protocol (LDP). This new protocol was exclusively defined to distribute MPLS label bindings with a set of mechanisms by which Label-Switched Paths (LSPs) may get established by mapping Forwarding Equivalence Classes ...
