COAP vs MQTT | Difference between COAP and MQTT protocols

This page compares COAP vs MQTT and mentions difference between COAP and MQTT protocols.

COAP Protocol

CoAP Architecture

• CoAP stands for Constrained Application Protocol.
• It is specified in RFC 7252.It is open IETF standard
• It is very efficient RESTful protocol.
• Easy to proxy to/from HTTP.
• It is Embedded web transfer protocol (coap://)
• It uses asynchronous transaction model.
• UDP is binding with reliability and multicast support.
• GET, POST, PUT and DELETE methods are used.
• URI is supported.
• It uses small and simple 4 byte header.
• Supports binding to UDP, SMS and TCP.
• DTLS based PSK, RPK and certificate security is used.
• uses subset of MIME types and HTTP response codes.
• Uses built in discovery mechanism.
Refer CoAP Protocol>> for more information.

MQTT Protocol

Broker based MQTT protocol

The figure-1 depicts simple MQTT protocol architecture (broker based). Following are the features of MQTT protocol:
• It is over TCP.
• It uses SSL/TLS for security.
• There are many messages used in MQTT protocol such as CONNECT, PUBLISH, SUBSCRIBE, DISCONNECT etc.
• Username/Password is used in 'connect' message.
• It encrypts payload i.e. it is payload agnostic.
• 1883 port is used by MQTT protocol.
Refer tutorial on MQTT Protocol>> for more information.

Following table compares various features of COAP vs MQTT and tabulates difference between CoAP and MQTT protocols.

Features CoAP MQTT
Full Form Constrained Application Protocol Message Queue Telemetry Transport
Model used for communication Request-Response, Publish-Subscribe Publish-Subscribe
RESTful Yes No
Transport layer Preferably UDP, TCP can also be used. Preferably TCP, UDP can also be used (MQTT-S).
Header Size 4 Bytes 2 Bytes
Number of message types used 4 16
Messaging Asynchronous & Synchronous Asynchronous
Application Reliability 2 Levels 3 Levels
Security IPSEC or DTLS Not defined in the standard
Intermediaries YES YES (MQTT-S)
LLN Suitability (thousand nodes) Excellent Fair
Application success stories Utility Field Area Networks Extending enterprise messaging into IoT applications

IoT Wireless Technologies

WLAN    ➤THREAD    ➤EnOcean    ➤LoRa    ➤SIGFOX    ➤WHDI    ➤Zigbee   ➤6LoWPAN   ➤Zigbee RF4CE   ➤Z-Wave   ➤NFC   ➤RFID   ➤INSTEON  

Difference between CoAP vs MQTT vs HTTP, MQTT vs DDS, MQTT vs REST, MQTT vs SMQTT

CoAP vs HTTP >>   MQTT vs HTTP >>   MQTT vs REST >>   MQTT vs DDS >>   MQTT vs SMQTT >>  

What is difference between

Difference between OSI and TCPIP layers  Difference between TCP UDP  FTP vs HTTP   FTP vs SMTP   FTP vs TFTP   ARP vs RARP   NAT vs PAT   RIP vs OSPF  SLIP vs PPP  IMAP4 vs POP3  IPV4 vs IPV6 

RF and Wireless Terminologies