When it comes to transport network, these days very hot discussion in the networking community is the comparison between Segment Routing, LDP and RSVP.
All of these three protocols can provide transport infrastructure for the network and on top of these protocols MPLS L2 VPNs, L3VPN and even Internet services are provided.
More and more network deploy Segment Routing.
LDP was the most common one since years and RSVP finds it's place in the networks commonly for the Fast Reroute capability of the protocol.
I recorded a video with Jeff Tantsura, and discussed the pros and cons of different transport mechanisms and comparing Segment Routing , LDP and RSVP from many different perspectives.
If you would choose one of these protocols, or considering migration, watch this video first.
Also, if you have any question or comment, you can share the comment section of this post.