4452d530_able___FreeSWITCH___Confluence__Description
[ITU-T Q.850 Code] 29 [SIP Equiv.] 501 [Enumeration] FACILITY_REJECTED [Cause] facilities rejected [Q.850] [Description] 
This cause is returned when a supplementary service requested by the user cannot be provide by the network.
Hangup Cause Code Table - FreeSWITCH - Confluence
Description