Internet Engineering Task Force (IETF) C. Bormann Request for Comments: 7959 Universitaet Bremen TZI Updates: 7252 Z. Shelby, Ed. Category: Standards Track ARM ISSN: 2070-1721 August 2016 Block-Wise Transfers in the Constrained Application Protocol (CoAP) Abstract 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 fragmentat
