5 ms·

SCTP has always looked intriguing to me, but would most backbones and ISPs pass it natively? It sounds like it would be a waste to tunnel it in UDP, which is t

SCTP has always looked intriguing to me, but would most backbones and ISPs pass it natively? It sounds like it would be a waste to tunnel it in UDP, which is the alternative...

_delirium 13y ago
The poor prospects for getting widespread SCTP support was one (though not the only) justification the SPDY people cited for doing some similar things at the application-protocol level: http://www.chromium.org/spdy/spdy-whitepaper http://www.chromium.org/spdy/spdy-whitepaper
derefr 13y ago
WebRTC Data Channels are, in fact, SCTP tunnelled over UDP (or rather, over DTLS over UDP.) They work pretty well. (I'm not sure how much of the redundancy is shaved off--does anyone know if WebRTC's tries to encapsulate "normative" SCTP, or whether it uses SCTP without checksum/port information?)
- rdtsc 13y ago
  Yeah not sure either, good question. There is also QUIC protocol also by Google, which is yet another crack at solving the problem. Wonder if those 2 groups sat down and discussed merging or re-using code.
MichaelGG 13y ago
Backbones and most ISPs are gonna route IP packets regardless of content. Until you hit a NAT or firewall and everything that's not UDP or TCP gets dropped.
noselasd 13y ago
Yes they would. The real problem is your home router/gateway/modem will not - and you're normally behind a NAT, which in all likelyhood does not know anything about SCTP (SCTP also isn't very NAT friendly).
- fulafel 13y ago
  Sctp only breaks if the ISP or user has turned on NAT. A router wouldn't break it. NAT does bad things to IP (breaks the fundamental guarantees).
  - hueving 13y ago
    >Sctp only breaks if the ISP or user has turned on NAT. This describes 95%+ of home users. NAT may do bad things to IP, but if you are an app developer that depends on no NAT, you're product is going to have a very limited market of people that can use it.
    - fulafel 13y ago
      IPv6!
      - mfukar 13y ago
        NAT isn't going away with IPv6.
        fulafel 13y ago
        IPv4 NAT is not, but you can sidestep it by using IPv6. Look at eg how XBox One is doing it. Or are you predicting the rise of IPv6 NAT?
        piranha 13y ago
        What is Xbox One doing?
        fulafel 13y ago
        They are tunneling IPv6 over Teredo if native IPv6 is unavailable. They provide their own relay servers for people who have NAT traversal incapable connectivity. Teredo is a Microsoft-developed (but IETF-standadized) NAT-traversing IPv6-over-IPv4 tunneling method. http://www.internetsociety.org/deploy360/blog/2013/10/microsoft-the-best-xbox-one-gaming-experience-will-be-over-ipv6/ http://www.internetsociety.org/deploy360/blog/2013/10/micros... http://www.ietf.org/proceedings/88/slides/slides-88-v6ops-0.pdf http://www.ietf.org/proceedings/88/slides/slides-88-v6ops-0....

SCTP has always looked intriguing to me, but would most backbones and ISPs pass it natively? It sounds like it would be a waste to tunnel it in UDP, which is the alternative...

_delirium 13y ago

The poor prospects for getting widespread SCTP support was one (though not the only) justification the SPDY people cited for doing some similar things at the application-protocol level: http://www.chromium.org/spdy/spdy-whitepaper http://www.chromium.org/spdy/spdy-whitepaper

derefr 13y ago

WebRTC Data Channels are, in fact, SCTP tunnelled over UDP (or rather, over DTLS over UDP.) They work pretty well. (I'm not sure how much of the redundancy is shaved off--does anyone know if WebRTC's tries to encapsulate "normative" SCTP, or whether it uses SCTP without checksum/port information?)

rdtsc 13y ago
Yeah not sure either, good question. There is also QUIC protocol also by Google, which is yet another crack at solving the problem. Wonder if those 2 groups sat down and discussed merging or re-using code.

MichaelGG 13y ago

Backbones and most ISPs are gonna route IP packets regardless of content. Until you hit a NAT or firewall and everything that's not UDP or TCP gets dropped.

noselasd 13y ago

Yes they would. The real problem is your home router/gateway/modem will not - and you're normally behind a NAT, which in all likelyhood does not know anything about SCTP (SCTP also isn't very NAT friendly).

fulafel 13y ago
Sctp only breaks if the ISP or user has turned on NAT. A router wouldn't break it. NAT does bad things to IP (breaks the fundamental guarantees).
- hueving 13y ago
  >Sctp only breaks if the ISP or user has turned on NAT. This describes 95%+ of home users. NAT may do bad things to IP, but if you are an app developer that depends on no NAT, you're product is going to have a very limited market of people that can use it.
  - fulafel 13y ago
    IPv6!
    - mfukar 13y ago
      NAT isn't going away with IPv6.
      - fulafel 13y ago
        IPv4 NAT is not, but you can sidestep it by using IPv6. Look at eg how XBox One is doing it. Or are you predicting the rise of IPv6 NAT?
        piranha 13y ago
        What is Xbox One doing?
        fulafel 13y ago
        They are tunneling IPv6 over Teredo if native IPv6 is unavailable. They provide their own relay servers for people who have NAT traversal incapable connectivity. Teredo is a Microsoft-developed (but IETF-standadized) NAT-traversing IPv6-over-IPv4 tunneling method. http://www.internetsociety.org/deploy360/blog/2013/10/microsoft-the-best-xbox-one-gaming-experience-will-be-over-ipv6/ http://www.internetsociety.org/deploy360/blog/2013/10/micros... http://www.ietf.org/proceedings/88/slides/slides-88-v6ops-0.pdf http://www.ietf.org/proceedings/88/slides/slides-88-v6ops-0....