4452d530_able___FreeSWITCH___Confluence__Description
[ITU-T Q.850 Code] 0 [Enumeration] UNSPECIFIED [Cause] Unspecified. No other cause codes applicable. [Description] 
This is usually given by the router when none of the other codes apply. This cause usually occurs in the same type of situations as cause 1, cause 88, and cause 100.
Hangup Cause Code Table - FreeSWITCH - Confluence
Description