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Subject: Re: [OMPI devel] iWARP development
From: George Bosilca (bosilca_at_[hidden])
Date: 2013-12-11 18:44:18


Don’t look in the 1.7.3 for SCTP. Instead, take a look at the trunk where we still have the SCTP BTL (ompi/mca/btl/sctp).

  George.

On Dec 11, 2013, at 17:33 , Prindeville, Philip <philip.prindeville_at_[hidden]> wrote:

> Hi.
>
> I was wondering what the current state of iWARP development is. There are some features we’re interested in, and from what I can tell the iWARP RFCs/Internet Drafts haven’t caught up to related developments. Part of our interest is in using SCTP as the LLP for iWARP, and updating that adaptation to the latest SCTP work.
>
> For instance:
>
> RFC 6458 – SCTP authentication
> RFC 6458 – SCTP out-of-order delivery
> RFC 6458 – SCTP association end-point address changes
> RFC 6458 – SCTP Receive Information
> RFC 6458 – SCTP partially reliable delivery
> RFC 6458 – SCTP key management
> RFC 5061 – SCTP Dynamic address reconfiguration (useful for hot NIC swaps in a high availability environment)
>
> We’d also like to see load-sharing in multipath environments, and sender-side traffic shaping support.
>
> From what I can tell, the iWARP SCTP work that’s been done predates RFC-6458, and hence I’m assuming it’s aligned to RFC-5043.
>
> Other questions I have:
>
> Has this code been tested extensively on non-x86 platforms? What about IA64, PPC64, ARM7, or MIPS 7K?
>
> Is anyone doing any code to port SolarFlare OpenOnload stack to support Open MPI’s iWARP?
>
> And a minor note… Just looking at the 1.7.3 tarball and grepping for SCTP in it, I find only a few matches, such as this:
>
> evutil_getaddrinfo_infer_protocols(struct evutil_addrinfo *hints)
> {
> …
> #ifdef IPPROTO_SCTP
> else if (hints->ai_protocol == IPPROTO_SCTP)
> hints->ai_socktype = SOCK_STREAM;
> #endif
> }
> }
>
> And this has me puzzled: SCTP is predominately a SOCK_SEQPACKET, isn’t it? (The whole point of using it and not TCP as a transport is it preserves record boundaries, supports out-of-order delivery and message interleaving, etc.)
>
> At least, that’s how it registers itself as a protocol in Linux 3.12 in net/sctp/protocol.c …
>
> Apologies if there’s a better mailing list for iWARP specific questions. I’m looking at a lot of this stuff for the first time and having to ramp up quickly.
>
> Thanks,
>
> -Philip
>
>
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