4452d530_able___FreeSWITCH___Confluence__Description
[ITU-T Q.850 Code] 52 [SIP Equiv.] 403 [Enumeration] OUTGOING_CALL_BARRED [Cause] outgoing calls barred [Description] 
This cause indicates that although the calling party is a member of the CUG for the outgoing CUG call, outgoing calls are not allowed for this member of the CUG.
Hangup Cause Code Table - FreeSWITCH - Confluence
Description