4452d530_able___FreeSWITCH___Confluence__Description
[ITU-T Q.850 Code] 47 [Cause] resource unavailable, unspecified [Q.850] [Description] 
This cause is used to report a resource unavailable event only when no other cause in the resource unavailable class applies.
Hangup Cause Code Table - FreeSWITCH - Confluence
Description