Disadvantages to CoAP

There are also some disadvantages to CoAP:

• Message unreliability: UDP does not guarantee the delivery of datagrams. CoAP adds a method to request a confirmation acknowledgement to confirm the message was received. This does not verify that it was received in its entirety and decoded properly.
• Standards are still maturing: CoAP is still evolving, although there is a lot of market momentum behind it. It is likely to mature quickly as use becomes more widespread.
• NAT issues: Network Address Translation (NAT) devices are commonly used in enterprise networks and cloud environments. CoAP can have problems communicating with devices behind a NAT since the IP can be dynamic over time.
• Security: Like MQTT, CoAP is unencrypted by default. This makes it natively unsecure and you need to take additional steps to make sure communication is not open to hackers.