L.1 General

33.1803GPPRelease 17Security of the Mission Critical (MC) serviceTS

The MC Security Gateway is a network function that terminates all 3GPP MC security functionality from a protected 3GPP MC system to allow MC signalling and media to be provided to an unprotected MC system or external system. The use of a MC Security Gateway is required when the system that the user wishes to communicate with does not support MC security mechanisms defined in this specification.

The SeGy is a network element in its own right. It may also be used as part of a Interworking Function (IWF) when the IWF requires MC security functionality to be terminated.

The use of a MC Security Gateway terminates end-to-end 3GPP protected media and signalling security. For this reason, a notification shall be provided to the MC user by the MC client when the user’s communication involves a MC Security Gateway.

Protection of media and signalling within an external system is out of scope for this standard, and therefore the external system is responsible for ensuring that both signalling and media within the external system are appropriately protected.