Peter - thanks for sharing this! For background, EnerNOC has used XMPP internally for our enterprise-to-device communications for years now, and we've been driving XMPP specification for OpenADR. To give some context, OpenADR is a complex multi-protocol (HTTP and XMPP) specification and we've purposely limited some of the XMPP features that we use, to maintain a certain level of parity between XMPP and HTTP. Many of the OpenADR alliance members have never used XMPP and we tried to keep things simple to make adoption easier, while still giving some of the immediate benefits over HTTP. Our hope is that we can optimize and take advantage of more XMPP features in future versions of the OpenADR spec as we gain experience. To answer some possible FAQs: - Why not use messages? All OpenADR service operations currently expect a response, and the response contains relevant info. In the future, some operations could possibly be optimized to assume message delivery and a "OK" response by default. - Why not use pub-sub? While some event dispatches could be multicast to many clients (VENs) the spec assumes the event payload can contain unique info per client. So a separate payload must be created for each client. But another possible opportunity for optimization nonetheless. Also, we've purposely limited (but not eliminated) the use of presence for two reasons: - Consumer end nodes (VENs) should not be aware of other VENs, only the VTN (the coordinator/ virtual top node) - a top node with thousands or millions of VENs subscribed to its presence presents a performance issue. Some more context: OpenADR is a "high level" energy communication schema that attempts to avoid "direct load control" e.g. Directly interacting with actuators. OpenADR communicates event information and assumes the VEN (client end point) will decide on discrete actions to perform. Similarly, OpenADR supplies "reports" but no direct sensor access. In this way, I think OpenADR is very complementary to the other XMPP IoT efforts going on right now. Open to any comments and feedback from XMPP experts! Thanks! -Thom Thom Nichols Principal Engineer, Advanced Technology Twitter: @thom_nic | Skype: thom.nichols o: 617.532.8154 | m: 401.323.1813 http://open.enernoc.com EnerNOC - get more from energy On 6/20/13 10:43 AM, "Peter Saint-Andre" <stpeter(a)stpeter.im> wrote: This email and any information disclosed in connection herewith, whether written or oral, is the property of EnerNOC, Inc. and is intended only for the person or entity to which it is addressed. This email may contain information that is privileged, confidential or otherwise protected from disclosure. Distributing or copying any information contained in this email to anyone other than the intended recipient is strictly prohibited.