What does Cisco Jabber require before SIP OAuth mode can be enabled?

Client Locally Significant Certificates are primarily used for mutual TLS authentication, which is distinct from the token-based authentication mechanism of OAuth.

An activation code is sometimes used for initial device provisioning or software licensing, but it is not a direct prerequisite for enabling SIP OAuth mode itself.

Cisco Jabber requires a JSON Web Token (JWT) when SIP OAuth mode is enabled, as the JWT serves as the secure access token exchanged between the Jabber client, the Identity Provider (IdP), and Cisco Unified Communications Manager for authentication. The JWT contains claims that verify the user's identity and permissions for SIP registration and other services.

While a JWT is a type of self-contained token, "self-contained token" is a generic term, and JWT is the specific, standardized technology required by Cisco for SIP OAuth.