News for hackers. Stuff that matters.

A comment on DCCP: a new transport layer protocol which draws from TCP and UDP.

Re:DCCP: a new transport layer protocol which draws from TCP... by yoaviram on Sunday January 01, 2017 @05:55AM (#13295391)
There's also SCTP:

Stream Control Transmission Protocol (SCTP) is a transport-layer protocol, serving in a similar role to the popular protocols TCP and UDP. It is standardized by IETF in RFC 4960.

SCTP provides some of the same service features of both: it is message-oriented like UDP and ensures reliable, in-sequence transport of messages with congestion control like TCP; it differs from these in providing multi-homing and redundant paths to increase resilience and reliability.

https://en.m.wikipedia.org/wiki/Stream_Control_Transmission_...

Edit: fix typo

[ Parent | on HN ]
Re:DCCP: a new transport layer protocol which draws from TCP... by IgorPartola on Sunday January 01, 2017 @02:50PM (#13296981)
HTTP should have made SCTP a lot more popular. SCTP is a natural fit for reliably transporting static files, which is what HTTP was originally designed for. So many of the HTTP2/SPDY/etc. features are there to make up for the fact that TCP doesn't have a length "field" since it's stream-oriented.

Obviously, there are exceptions and you can have both streams and known-length content served over HTTP, but I still think streams over SCTP would have been a better choice than datagrams over TCP.

Edit: Also firewalls that filter out anything but TCP (or TCP + UDP, or TCP + UDP + ICMP) can die a fiery death. The fact that basically any new protocol has to tunnel over UDP instead of properly over IP is heresy and bullshit.

[ Parent | on HN ]
Re:DCCP: a new transport layer protocol which draws from TCP... by voidz on Sunday January 01, 2017 @06:08AM (#13295407)
It's also (usually) routed over the Internet properly in my experience.
[ Parent | on HN ]
Re:DCCP: a new transport layer protocol which draws from TCP... by kosinus on Sunday January 01, 2017 @07:35AM (#13295550)
SCTP may see more usage in the wild because of WebRTC.
[ Parent | on HN ]
Re:DCCP: a new transport layer protocol which draws from TCP... by unmole on Sunday January 01, 2017 @08:00AM (#13295602)
WebRTC does not use real SCTP but a rather a tunnel over UDP. Besides, it's not like WebRTC accounts for a significant amount of Internet traffic. I'd say SCTP sees more usage simply because it has been around for much longer with SS7 being the primary use case.
[ Parent | on HN ]
Re:DCCP: a new transport layer protocol which draws from TCP... by atlas1j on Sunday January 01, 2017 @11:53AM (#13296259)
There is a standards track RFC that defines SCTP over UDP. RFC 6951 "UDP Encapsulation of Stream Control Transmission Protocol (SCTP) Packets for End-Host to End-Host Communication".
[ Parent | on HN ]
Re:DCCP: a new transport layer protocol which draws from TCP... by unmole on Sunday January 01, 2017 @12:13PM (#13296318)
Sure. But it's still not real SCTP if the IP header's Protocol field doesn't say 0x84 :D
[ Parent | on HN ]
Re:DCCP: a new transport layer protocol which draws from TCP... by ycmbntrthrwaway on Sunday January 01, 2017 @01:00PM (#13296547)
Also QUIC, which got most of its ideas from SCTP and some from DCCP.
[ Parent | on HN ]
Re:DCCP: a new transport layer protocol which draws from TCP... by epx on Sunday January 01, 2017 @01:17PM (#13296613)
SCTP really really deserved to be widely deployed.
[ Parent | on HN ]
Re:DCCP: a new transport layer protocol which draws from TCP... by nickpsecurity on Sunday January 01, 2017 @02:10PM (#13296804)
And UDT which was winning awards for performance on supercomputers since around 2007:

http://udt.sourceforge.net/

[ Parent | on HN ]