Recommendation ITU-T X.1153 provides a management framework of a one time password (OTP)‑based authentication service to support multi-factor authentication. Specifically, this Recommendation includes the general management framework, the centralized management framework, the enhanced centralized framework, and the cross-domain management framework. These frameworks consist of the OTP management models, OTP management operations, and security considerations for providing the OTP authentication service in a secure telecommunication network.