Что такое MPLS?

https://datatracker.ietf.org/doc/rfc3251/

   Mostly Pointless Lamp Switching (MPLampS) is an architecture for
   carrying electricity over IP (with an MPLS control plane).  According
   to our marketing department, MPLampS has the potential to
   dramatically lower the price, ease the distribution and usage, and
   improve the manageability of delivering electricity.  This document
   is motivated by such work as SONET/SDH over IP/MPLS (with apologies
   to the authors).  Readers of the previous work have been observed
   scratching their heads and muttering, "What next?".  This document
   answers that question.

Там есть и LDS, LSR, RSVP, CRLDP, OSPF, ISIS, VPN, ITU, COPS.