Monday, July 21, 2014

IoT: CoAP: Constrained Application Protocol (!)

Constrained Application Protocol - Wikipedia, the free encyclopedia:

"Constrained Application Protocol (CoAP) is a software protocol intended to be used in very simple electronics devices that allows them to communicate interactively over the Internet. It is particularly targeted for small low power sensors, switches, valves and similar components that need to be controlled or supervised remotely, through standard Internet networks. CoAP is an application layer protocol that is intended for use in resource-constrained internet devices, such as WSN nodes. CoAP is designed to easily translate to HTTP for simplified integration with the web, while also meeting specialized requirements such as multicast support, very low overhead, and simplicity.
...
CoAP makes use of two message types, requests and responses, using a simple binary base header format. The base header may be followed by options in an optimized Type-Length-Value format. CoAP is by default bound to UDP and optionally to DTLS, providing a high level of communications security."


IoT: is MQTT spec a mess?

Clemens is a well known and experienced Microsoft engineer / architect, currently working on IoT solutions.
When trying to implement MQTT he observed some (many) issues with the (IBM's open sourced) spec.
This will clearly initiate active discussion, and that will likely be helpful for for future of IoT.

Clemens Vasters - MQTT. An Implementer’s Perspective:
"MQTT is an old, recycled, and often weirdly inconsistent mess. It's not a good protocol, and certainly not a good protocol for the Internet of Things where we will look connect devices with long-haul links with unpredictable network conditions, and I believe it's unfixable without becoming something different entirely. We ought to know better, and OASIS also ought to know better."

Clemens Vasters - MQTT discussion, continued …

MQTT V3.1 Protocol Specification @ IBM

A Critique of MQTT From a Microsoft Architect | Javalobby @ DZone

MQTT - Another Implementor's Perspective - Tim Kellogg

MQTT – a discussion on Clemens Vasters’ post (IBM messaging) @ IBM