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Re: [storm] DDP messages ordering

Tom Talpey <tom@talpey.com> Tue, 08 September 2015 14:15 UTC

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From: Tom Talpey <tom@talpey.com>
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Subject: Re: [storm] DDP messages ordering
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On 9/8/2015 6:02 AM, Elena Gurevich wrote:
> Hello,
>
> RFC 5041 section 5.3 stands that
>
> ----------------------------------
>
> 5.3 Ordering Among DDP Messages
>
> Messages passed through the DDP MUST conform to the ordering rules
>
> defined in this section.
>
> At the Data Source, DDP:
>
> * MUST transmit DDP Messages in the order they were submitted to
>
> the DDP layer,
>
> * SHOULD transmit DDP Segments within a DDP Message in increasing
>
> MO order for Untagged DDP Messages, and in increasing TO order
>
> for Tagged DDP Messages.
>
> ----------------------------------
>
> Does this mean that transmitter MUST not interleave DDM segments related
> to consequent DDP messages ?

It depends on what you mean by "the transmitter". It's certainly
possible that network delivery and TCP retransmission can reorder
segments. But the first rule requires that DDP not interleave two
separate operations when passing them to the TCP transport.

Tom.

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