you may find an answer to your question in the document:
GSMA IoT Security Assessment Checklist
https://www.gsma.com/iot/iot-security-assessment/
Some parts in the following security standards may be of interest to you:
ITU-T: Security in Telecommunications and Information Technology; An overview of issues and the deployment of existing ITU-T Recommendations for secure telecommunications, September 2015
ITU-T X.805: Security architecture for systems providing end-to-end communications
https://www.itu.int/rec/T-REC-X.805-200310-I/en
These ITU-T recommendations can be used as a guide for the development of security guidelines and can also serve as the basis for a security assessment.
By using the packet tracer, you will be able to build and operate your own network... So, you can easily manage and analysis the IoT and fix all the problems...