Because if you're going to start building a protocol on UDP from scratch today, you can do much better than SCTP based on what concerns you're trying to solve.

Because if you're going to start building a protocol on UDP from scratch today, you can do much better than SCTP based on what concerns you're trying to solve. Pretty much every new UDP protocol pays at least lip service to the mobile use-case, and tries to get to zero roundtrip session establishment for majority of sessions ( and here the 4-way handshake of SCTP sticks out like a sore thumb). But then there are some people who might be more interested in making a secure protocol from scratch (rejecting the layering complexity and third-party dependence of SSL). For instance: http://cr.yp.to/tcpip/minimalt-20130522.pdf http://cr.yp.to/tcpip/minimalt-20130522.pdf