requireRegistration

This flag should be SUPPORTED when the associated trunk group is used for endpoints optionally requiring registration. It should be REQUIRED in cases where absolutely no unregistered IAD may make any calls. It should be SUPPORTED-GROUP to allow calls from unregistered users and to allow calls from users whose username does not match with the stored URI. It should be REQUIRED-NONPRIORITY when unregistered IAD cannot make any non-priority calls. NONE (default) is selected when no registration validation is to be performed.