Submission to the IAB Workshop on Stack Evolution in a Middle-box Internet (SEMI)

It is very hard to deploy transport protocol innovations such as encryption, multipath or forward error correction. This is largely due to the assumptions made by middle-boxes, which contribute to a practical freeze of the TCP specifications. Protocol developers tends to see that as a technical problem, but it really is a tussle in which middle-box vendors and operators compete for Internet value against end to end devices and services. We have an example of a similar tussle in the past, between real-time applications on one hand, NATs and firewalls on the other. The NAT traversal tussle was solved with the unilateral deployment of a variety of protocols, which repositioned the balance of power between end-to-end and middle-boxes. Protocol developers need to adopt the same approach for fielding transport innovation, and that probably means an encrypted transport on top of UDP, so they can win the “secure transport tussle.