4452d530_able___FreeSWITCH___Confluence__Description
[ITU-T Q.850 Code] 54 [SIP Equiv.] 403 [Enumeration] INCOMING_CALL_BARRED [Cause] incoming calls barred [Description] 
This cause indicates that although the called party is a member of the CUG for the incoming CUG call, incoming calls are not allowed to this member of the CUG.
Hangup Cause Code Table - FreeSWITCH - Confluence
Description