Advantages to CoAP

There are some advantages to CoAP:

• Reduced power requirements: It operates over UDP, which requires minimal overhead for communications. It also allows faster wake up times and extended sleepy states. Taken together, this means batteries last longer for IoT devices.
• Smaller packet size: Another advantage of UDP is small packet sizes. This leads to faster communication cycles. Again, this allows batteries to last longer.
• Security: Like MQTT, this is on both the advantage and disadvantage lists. When Datagram Transport Layer Security (DTLS) is employed over UDP, communication is encrypted and secure. Even though there is some additional overhead required to implement this, you can and should use it.
• Asynchronous communication option: Clients can request to observe a device by setting a flag. The server (IoT device) can then stream state changes to the client as they happen. Either side can cancel the observe request.
• IPv6 based: It was designed from the beginning to support IPv6. This also allows for a multicasting option.
• Resource discovery: Servers can provide a list of resources and media types. The client can then review and discover what is available.