Re: New web of things server projects

Hi Vinob,

I urge you to read the draft ;-) Observe is indeed used for notification in CoAP PubSub, but there is more to PubSub that warrants a separate draft.

Observe in CoAP is used to send data asynchronously from the server to a client. With CoAP, the end device is usually assumed to be a server, but the main idea in CoAP PubSub is to move the server role to a pubsub broker and make the end device a client. The end device uses PUT to publish updates to the broker, and GET or Observe to receive updates from the broker.

Application software or peer devices can receive asynchronous updates from the device forwarded by the broker using normal CoAP Observe.

This pattern is useful in that it enables the end device to sleep between updates and also to operate behind a NAT firewall without special configuration. It also should provide a natural binding to other PubSub systems like MQTT.

Please continue this discussion at core@ietf.org 

Thanks!

Michael

PS Sorry for the duplicate posts below…


On Jun 25, 2015, at 4:44 PM, R.Vinob chander <vinobchanderr@ssn.edu.in> wrote:

> Hi Michael,
> 
>    Just wondering how is coap-pubsub different from the Observe extention to CoAP. Why another push spec. might be required? If it has additional new features, why not merge with Observe. 
> 
> Thanks
> Vinob
> 
> On Fri, Jun 26, 2015 at 4:54 AM, Michael Koster <michaeljohnkoster@gmail.com> wrote:
> 
> On Jun 25, 2015, at 11:22 AM, Dave Raggett <dsr@w3.org> wrote:
> 
>> 
>> For CoAP I would like to take advantage of the pub-sub mechanism that the IETF is working on, as a basis for the thing server to send notifications to other servers with proxies for the things that the CoAP server hosts.  I am chatting with some MQTT experts to ensure that we hit the ground running with the MQTT bindings.   A further challenge is the choice of binary encodings for messages.  Carsten Bormann of CoAP fame advocates CBOR, but other people are keen on EXI, which can offer superior compression based upon the data model.
>> 
> 
> 
> Hi Dave,
> 
> I’m also the draft editor for CoAP PubSub, and am working on updating the document this week. 
> 
> https://datatracker.ietf.org/doc/draft-koster-core-coap-pubsub/
> 
> Sorry for the slight off-topic but I would appreciate feedback from this group on this draft if anyone would care to review it. Please email me with comments and suggestions.
> 
> Thanks!
> 
> Michael J. Koster
> 
> 
> 
> -- 
> R. Vinob chander, B.E., M.E., (Ph.D)
> Assistant Professor, Department of IT
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