Re: Tagged vs Untagged wrt providing message length

On Jan 19, 2004, at 10:46 AM, Barry Reinhold wrote:

> Hemal (or whomever wishes to post),
> 	Clause 7.4 states that:
>
> "At the Data Sink, DDP MUST provide the ULP Message Length to the ULP
>    when an Untagged DDP Message is Delivered."
>
> Is it thus not required that the length be provided for Tagged DDP
> messages?
>
> I guess I am unclear as to why length is needed for the untagged but 
> not
> for the tagged.
>
> Barry Reinhold
> Lamprey Networks
> [email protected]
> (603) 868-8411
>

Normally DDP provides no notification of tagged placements
to the ULP -- except that delivery of an untagged message
cannot take place until all *prior* tagged messages have
been fully placed.

Further, even though the standard does not state that the
DDP layer MUST NOT tell the ULP about individual tagged
placements, the ULP MUST NOT use the buffers until the
trailing untagged message is delivered. So there wouldn't
be any point in supplying that information.

The benefits of suppressing ULP interactions for tagged
messages is covered in the applicability statement.

http://www.ietf.org/internet-drafts/draft-ietf-rddp-applicability-01.txt





-- 
Caitlin Bestler - [email protected] - http://asomi.com/
http://asomi.com/CaitlinBestlerPublicPgpKey.html