Re: [core] Using CoAP for P2P

Mehmet Adalier <> Thu, 02 April 2020 19:24 UTC

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Date: Thu, 02 Apr 2020 12:23:49 -0700
From: Mehmet Adalier <>
To: Christer Holmberg <>, Abhijan Bhattacharyya <>, Thomas Fossati <>
CC: core <>
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Thread-Topic: [core] Using CoAP for P2P
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Subject: Re: [core] Using CoAP for P2P
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As far as I know, a CoAP node can be provisioned to provide both client and server functionality and change the behavior as required (i.e. act as a client when it is doing client work and act as a server/resource when doing server work). Our implementation runs a daemon that can instantiate multiple clients/servers on a single computing node.


If you do not want to set up a Broker/Intermediary as a separate node (e.g., pubsub), then you can make one of your nodes also a “a broker”

and create your topics on that one (e.g., chatboard topic). Then each node can subscribe to the topic as well as publish to the topic. 

The described approach will support P2P and reduce traffic.




From: core <> on behalf of Christer Holmberg <>
Date: Thursday, April 2, 2020 at 11:41 AM
To: Abhijan Bhattacharyya <>om>, Thomas Fossati <>
Cc: core <>
Subject: Re: [core] Using CoAP for P2P




If you are interested in P2P, you might be interested in the thin-ICE presentation that was given at the T2TRG meeting in Singapore:







From: core <> on behalf of Abhijan Bhattacharyya <>
Date: Thursday, 2 April 2020 at 11.04
To: Thomas Fossati <>
Cc: core <>
Subject: Re: [core] Using CoAP for P2P


Hi Thomas, 

What I am looking at is a situation where I have two nodes each having a time-varying resource. Both want to push the states of the respective resource to the other node within a common application context. However, these exchanges are naturally asynchronous. May be I can think of it more like a chat. A typical client-server or observe relationship will not serve the purpose. Actually both should have a client and server instance running under a common application. Then either each can *observe* the other, or can *post* the other. That is how we can do that without a central server.


If my understanding is right, according to CoAP specification, the nodes which can have both server and client (to the origin server) are "intermediary" nodes. The only example of "intermediary" considered in the spec is the proxy node. But, anyway the situation in this case does not concern with intermediary. Both are origin server and end-client together.


Is there any standardized mechanism to handle this situation?




On Wed, Apr 1, 2020 at 5:32 PM Thomas Fossati <> wrote:

Hi Abhijan,

On 01/04/2020, 12:31, Abhijan Bhattacharyya <> wrote:
> Is there any standardized mechanism to use CoAP for a P2P connection?

Not sure whether RFC 7650 would fit your needs but worth having a
look -- if you haven't already.


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Abhijan Bhattacharyya,

Technologist by profession [IoT| Internet Protocols| 5G]

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