That's hardly integrated into a shipping IP stack. FreeBSD may be an SCTP reference implementation, but that's not significant deployment.
-----Original Message----- From: Michael Tüxen [mailto:[email protected]] Sent: 27 April 2010 19:16 To: Wood L Dr (Electronic Eng) Cc: [email protected]; [email protected]; [email protected]; [email protected] Subject: Re: UDP encaps for SCTP and SCCP On Apr 26, 2010, at 10:34 PM, <[email protected]> <[email protected]> wrote: > > On 26 Apr 2010, at 20:07, Jukka Manner wrote: > >> Hi Lloyd, >> >> I have to object here. :) >> >> On 22.4.2010 13:50, [email protected] wrote: >> >>> The GUT draft and recreating IP packets strikes me as problematic in >>> implementation, just as much as NATs. I'd rather have a simple >>> IP-in-IP-tunnel (or even GRE) and rely on decap at the endpoints... >>> >> >> GUT is not problematic, nor difficult. We have it running on Linux >> and works great. Next we'll put it on BSD (should be just a medium >> update to the code). I'm hoping to release the implementation as open >> source sometime in the future. >> >> Our draft could be much better in explaining the idea clearly. The >> fact that we are "creating ip packets" is due to our implementation >> being a separate piece of code, a separate service on the OS, easily >> installed. > > No. You are "_re_creating IP packets" in that you are not carrying the > IP header end-to-end, but are carrying minimal state to recreate an > approximation of the original IP header. That makes me nervous. (This > is not link header compression.) > > You are not encapsulating the IP protocol header, but eviscerating it. You > call that "reconstruct the native IP packet" or "rebuild the IP packet". > > http://tools.ietf.org/html/draft-manner-tsvwg-gut-01 > (can I suggest a spelling checker for the typos?) > > The summary benefits you state in section 8 work for a normal UDP tunnel, and > with rather less complexity. > > On a related note, I spent years dealing with proponents of SCTP, and yet > never encountered any actual we-chose-to-use-SCTP end users. So, are there > any actual DCCP users out there? > > All this effort to save a few bytes tunnelling complex protocols that still > won't be used? Pointless. > >> The functionality could be as well be integrated into the IP stack, >> but that would be somewhat more challenging. > > ...and won't happen. The SCTP/UDP encapsulation is implemented in FreeBSD and part of the SCTP kernel implementation for Mac OS X. Best regards Michael > > L. > >> >> regards, >> Jukka > > Lloyd Wood > [email protected] > http://sat-net.com/L.Wood > > > >
