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Block-Wise Transfers in the Constrained Application Protocol (CoAP)
RFC 7959

Revision differences

Document history

Date By Action
2023-07-08
(System) Received changes through RFC Editor sync (added Verified Errata tag)
2020-04-11
(System) Received changes through RFC Editor sync (added Errata tag)
2018-12-20
(System)
Received changes through RFC Editor sync (changed abstract to 'The Constrained Application Protocol (CoAP) is a RESTful transfer protocol for constrained nodes and networks. Basic …
Received changes through RFC Editor sync (changed abstract to 'The Constrained Application Protocol (CoAP) is a RESTful transfer protocol for constrained nodes and networks. Basic CoAP messages work well for small payloads from sensors and actuators; however, applications will need to transfer larger payloads occasionally -- for instance, for firmware updates. In contrast to HTTP, where TCP does the grunt work of segmenting and resequencing, CoAP is based on datagram transports such as UDP or Datagram Transport Layer Security (DTLS). These transports only offer fragmentation, which is even more problematic in constrained nodes and networks, limiting the maximum size of resource representations that can practically be transferred.

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

A CoAP implementation that does not support these options generally is limited in the size of the representations that can be exchanged, so there is an expectation that the Block options will be widely used in CoAP implementations. Therefore, this specification updates RFC 7252.')
2018-07-26
Jenny Bui Posted related IPR disclosure: Huawei Technologies Co.,Ltd's Statement about IPR related to RFC 7959
2016-08-26
(System)
Received changes through RFC Editor sync (created alias RFC 7959, changed title to 'Block-Wise Transfers in the Constrained Application Protocol (CoAP)', changed abstract to …
Received changes through RFC Editor sync (created alias RFC 7959, changed title to 'Block-Wise Transfers in the Constrained Application Protocol (CoAP)', changed abstract to 'The Constrained Application Protocol (CoAP) is a RESTful transfer protocol for constrained nodes and networks. Basic CoAP messages work well for small payloads from sensors and actuators; however, applications will need to transfer larger payloads occasionally -- for instance, for firmware updates. In contrast to HTTP, where TCP does the grunt work of segmenting and resequencing, CoAP is based on datagram transports such as UDP or Datagram Transport Layer Security (DTLS). These transports only offer fragmentation, which is even more problematic in constrained nodes and networks, limiting the maximum size of resource representations that can practically be transferred.', changed pages to 37, changed standardization level to Proposed Standard, changed state to RFC, added RFC published event at 2016-08-26, changed IESG state to RFC Published, created updates relation between draft-ietf-core-block and RFC 7252)
2016-08-26
(System) RFC published