Re: [tsvwg] comments draft-tuexen-tsvwg-sctp-prpolicies-01

[Michael Tuexen <[e-mail]>]

On Jul 10, 2013, at 3:22 AM, Jamal Hadi Salim <[e-mail]> wrote:

> 
> Hi,
> 
> Looks good. 
> I have an unrelated question since a mention occurs in the sprstat_abandoned_sent stats): 
> does it make sense to abandon a message that is partially sent? At the receiver, I am
> assuming if such a  partial message was to make it, partial delivery will be made to
> the socket user?
Ji Jamal,

you have to distinguish between the sender and receiver side.

Assume the sender sends a user message which is approximately of size 3*MTU.
So SCTP will fragment it into 3 DATA chunk and send them. If the user
has specified that the number of retransmissions is limited to 0 and
the last fragment gets lost in the network, the sender will increment
sprstat_abandoned_sent.

What will happen at the receiver side if you assume that the first two
fragments have been received. If partial delivery was started, you will
get a SCTP_PARTIAL_DELIVERY_EVENT event indicating SCTP_PARTIAL_DELIVERY_ABORTED.
Without partial delivery being started, the receiver could also drop the
first part of the message.

Best regards
Michael
> 
> 
> cheers,
> jamal
> 
>