4452d530_able___FreeSWITCH___Confluence__Description
[ITU-T Q.850 Code] 127 [Enumeration] INTERWORKING [Cause] Interworking, unspecified [Q.850] [Description] 
This cause indicates that an interworking call (usually a call to SW56 service) has ended.
Hangup Cause Code Table - FreeSWITCH - Confluence
Description