Subject: Last Call: <draft-ietf-core-block-18.txt> (Block-wise transfers in CoAP) to Proposed Standard

From: The IESG <[email-masked]>
Date: Fri, 20 Nov 2015 13:32:50 -0800

The IESG has received a request from the Constrained RESTful Environments
WG (core) to consider the following document:
- 'Block-wise transfers in CoAP'
  <draft-ietf-core-block-18.txt> as Proposed Standard

The IESG plans to make a decision in the next few weeks, and solicits
final comments on this action. Please send substantive comments to the
[email-masked] mailing lists by 2015-12-04. Exceptionally, comments may be
sent to [email-masked] instead. In either case, please retain the
beginning of the Subject line to allow automated sorting.

Abstract

   CoAP is a RESTful transfer protocol for constrained nodes and
   networks.  Basic CoAP messages work well for the small payloads we
   expect from temperature sensors, light switches, and similar
   building-automation devices.  Occasionally, however, applications
   will need to transfer larger payloads -- for instance, for firmware
   updates.  With HTTP, TCP does the grunt work of slicing large
   payloads up into multiple packets and ensuring that they all arrive
   and are handled in the right order.

   CoAP is based on datagram transports such as UDP or DTLS, which
   limits the maximum size of resource representations that can be
   transferred without too much fragmentation.  Although UDP supports
   larger payloads through IP fragmentation, it is limited to 64 KiB
   and, more importantly, doesn't really work well for constrained
   applications and networks.

   Instead of relying on IP fragmentation, this specification extends
   basic CoAP with a pair of "Block" options, for transferring multiple
   blocks of information from a resource representation in multiple
   request-response pairs.  In many important cases, the Block options
   enable a server to be truly stateless: the server can handle each
   block transfer separately, with no need for a connection setup or
   other server-side memory of previous block transfers.

   In summary, the Block options provide a minimal way to transfer
   larger representations in a block-wise fashion.

The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-core-block/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-core-block/ballot/

No IPR declarations have been submitted directly on this I-D.