MPLS is not a "successful" protocol

RFC 5218 defines what the Internet Architecture Board considers to be a "successful" protocol. A "successful" protocol is one that meets its original goals and is widely deployed, such as DNS, BGP, SMTP, and SIP. A "wildly successful" protocol far exceeds its original goals in terms of purpose and scale. Examples of the latter are IPv4, ARP, and HTTP. A protocol may be considered successful even