4452d530_able___FreeSWITCH___Confluence__Description
[ITU-T Q.850 Code] 66 [Enumeration] CHAN_NOT_IMPLEMENTED [Cause] channel type not implemented [Q.850] [Description] 
This cause indicates that the equipment sending this cause does not support the channel type requested
Hangup Cause Code Table - FreeSWITCH - Confluence
Description