In reply to Peter Waher.

Thanks all for your thoughtful feedback.

@Peter

Some of the comparisons you've provided are not quite apples to apples.

Rating CoAP and RESTful approaches as MEDIUM security because they do not inline security details or refer to external specs is a bit of a slippery slope. I can assure you that Cisco is currently deploying million node CoAP based Field Area Networks which implement best-of-breed, standards based, critical-infrastructure-grade security for node authentication, authorization, encryption, etc.

Same point re: provisioning. Zero touch node deployment is built into the Cisco Field Area Networks. One simply can not practically deploy a million node network without this capability.

Interoperability. You have rated most of the options as LOW on the point of payload interoperability. CoAP, HTTP etc are application protocols which, by design, do not specify payload semantics or encoding. That is left to various organizations which will build their interoperability profiles atop these app protocols. A recent example is the Smart Energy Profile 2 specification, which defines a full stack interop profile (based on a RESTful approach) for premises energy management. And Cisco (amongst others) is moving to do same for the FAN within the Wi-SUN Alliance.

Cisco does applaud the XEP work you've mentioned re: XMPP support for IoT/M2M. I hope that bears results soon.

@James and Dwight

AMQP got its start as a "wire level" messaging standard (versus, say, JMS ... which is API definition) for high speed transaction processing for the financial industry. One could say AMQP long ago supported M2M applications.

All that said, its important to note that there will be no "one size fits all" solution for IoT/M2M. Your technology selections will depend upon the requirements of your application (messaging patterns, network capabilities, security, currently deployed infrastructure, etc).