The present document specifies the configuration management documents and protocols needed to support Mission Critical Push To Talk (MCPTT) online configuration over the CSC-4 and CSC-5 reference points and the procedures to support Mission Critical Push To Talk (MCPTT) offline configuration over the CSC-11and CSC-12 reference points. Configuration management documents defined in the present document includes: MCPTT UE initial configuration document; MCPTT UE configuration document; MCPTT user profile configuration document; and MCPTT service configuration document. Mission critical communication services are services that require preferential handling compared to normal telecommunication services@ e.g. in support of police or fire brigade. The MCPTT service can be used for public safety applications and also for general commercial applications (e.g.@ utility companies and railways). The present document is applicable to an MCPTT UE supporting the configuration management client functionality@ to application server supporting the configuration management server functionality@ and to application server supporting the MCPTT server functionality.