Re: [core] draft-ietf-core-new-block: Congestion Control

[Jon Shallow <[e-mail]>]

Hi Michael,

The original concept of Quick-Block2 was to get all of the data over in an
efficient manner (subject to congestion control) and reduce the number of
requests needed as a part of that process.  An Observe trigger just needed
to send over all of the data within the body.

"Selective" access to resource data was not required but is provided by
Block2 (but missing blocks can be re-requested using Quick-Block2).  When
asked yesterday, I knew that there were likely to be issues in this area and
my answer was not well thought through - hence what you picked up.

It is possible to ask for a specific offset and the blocks following as the
Quick-Block2 option can be used multiple times in a single GET request -
they would be the base offset (as indicated by block.num and block.szx) and
the remaining options used for block.num+1, block.num+2 etc.  If more than
MAX_PAYLOAD options were defined, the first MAX_PAYLOAD would come back,
then an ACK_TIMEOUT pause and then the next blocks etc.

Regards

Jon

> -----Original Message-----
> From: Michael Richardson [mailto: [e-mail]]
> Sent: 23 October 2020 17:43
> To: [e-mail]
> Cc: [e-mail]
> Subject: Re: [core] draft-ietf-core-new-block: Congestion Control
> 
> If I understood yesterday, it is possible to send a single package asking
for
> a specific offset of data, and then get 10 packets worth of reply?
> 
> Is that correct?