Stack Overflow
Stack Overflow

Questions tagged [coap]

CoAP is an application protocol designed for constrained devices, designed to easily translate to HTTP.

203 questions
12
votes
4 answers

What are the major differences between HTTP and COAP?

HTTP is mainly used for viewing web pages. Coap is a simplified version of HTTP for IoT or WSNs. Although COAP is based on UDP, it should have ACK messages to emulate TCP. Since COAP is simpler than HTTP, it will have lower latency and draw less…
John Doyle
  • 756
  • 1
  • 7
  • 18
11
votes
2 answers

Is video streaming over IoT protocols feasible?

Can Video streaming (low bitrates like 50 Kbps ) could be done over IoT protocols like CoAP/MQTT with much better performances compared to HTTP/RTP or TCP/UDP streaming? Or underlying video streaming architecture does not help the use case using…
Main
  • 1,622
  • 3
  • 17
  • 27
9
votes
2 answers

CoAP and DTLS integration

I have implementation of CoAP (libcoap), and implementation of DTLS (tinyDTLS). How can I make integration CoAP (libcoap) with DTLS (tinyDTLS)? I will be grateful for the any advice.
Puzzle
  • 173
  • 2
  • 6
8
votes
4 answers

Using gRPC as a IoT protocol instead of LWM2M/CoAP

I have been toying with the idea of using gRPC for 'IoT' type devices; not very constrained things like sensors; more like single board computer inbuilt devices like robots, drones and the like. What is needed a interface between device and…
Alex Punnen
  • 3,420
  • 36
  • 52
8
votes
1 answer

What is the size of CoAP packet?

I'm new for this technology, can somebody help me to know about some doubt? Q-1. What is the size of CoAP packet? (I know there is 4 byte fixed header, but what is the maximum size limit including header, option and payload?) Q-2. Is there any…
Ankit
  • 171
  • 5
  • 13
5
votes
1 answer

IoT device with CoAP and NAT Traversal

Context: Each customer can have 100-1000 IoT-devices behind NAT. We have multiple customers. The aim is to manage these devices from outside. Devices use CoAP protocol, which uses by default udp. There are few constraints. It is not possible to…
Sukar Lofer
  • 53
  • 4
5
votes
3 answers

Californium CoAP path parameters

I'm working on a CoAP application using Eclipse Californium and I need to pass parameters using the URL as we do in restful web services. Is it possible to do it in californium coap implementation, and if so please let me know how to do…
Yasith Lokuge
  • 231
  • 3
  • 14
4
votes
1 answer

To support Keep-alive functionality of CoAP

I'm checking that CoAP can support keep-alive functionality like HTTP. Can CoAP support keep-alive functionality? If yes, how to set it up?
Jang
  • 142
  • 1
  • 2
  • 10
4
votes
1 answer

CoAP Too many observers

I want to 'Observe' resources in a CoAP server. But What I've noticed is that after I register to observe a few resources in the server, an additional resources I try to 'Observe' throw a message saying 'Too Many Observers' I'm using Copper…
Srihari S
  • 91
  • 1
  • 2
  • 10
4
votes
3 answers

MQTT and CoAP Sensors and Actuators

MQTT and CoAP are being promoted as standard protocols that allow connecting constrained devices to the Internet. I'm interested in a list of sensors and actuators that support these two protocols either in a native way or through a mesh/gateway.
Younes
  • 1,512
  • 1
  • 18
  • 31
4
votes
2 answers

Is there a way to send CoAP commands using JavaScript?

I was just wondering if there was a way to send CoAP queries in the browser (using JavaScript?), but not using node.js. Thanks!
Daryl Rodrigo
  • 1,157
  • 1
  • 8
  • 17
3
votes
2 answers

OneM2M coap client in node.js

I have to develop a node.js app which can interact with another oneM2M server. In particular the node.js app need to exchange data using CoaP protocol, but I don't know how to do that in a oneM2M compliant manner. I started my node.js project using…
vp-platform
  • 581
  • 5
  • 17
3
votes
1 answer

using express routing with non-http (coap)

I'm running a coap server, and as I've started adding routes, maintaining my own routing is a bit tedious so I thought I'd switch to express (which I already use for an http server). Now, given that it uses basically the same format for…
GTF
  • 6,353
  • 4
  • 27
  • 55
3
votes
2 answers

Does DTLS require sessions to timeout?

I'm trying to figure out the most data-use efficient way to secure our CoAP API. DTLS seems to be the right way to do it, but looking at how much data the handshake requires (and making some uninformed assumptions about how often that needs to…
Azdle
  • 1,763
  • 1
  • 14
  • 21
3
votes
1 answer

Coap blockwise transfer: How to map following blocks to initial block/request

Let's say I have a client that wants to send two large requests to the server (at the same time). Let's say the first payload is "ABCD" and the second payload is "WXYZ". First block of first request has messageID=1 and token=0x1 with payload…
Robert Ende
  • 376
  • 3
  • 11
1
2 3
…
13 14