4452d530_able___FreeSWITCH___Confluence__Description
[ITU-T Q.850 Code] 88 [SIP Equiv.] 488 [Enumeration] INCOMPATIBLE_DESTINATION [Cause] incompatible destination [Q.850] [Description] 
This cause indicates that the equipment sending this cause has received a request to establish a call which has low layer compatibility, high layer compatibility or other compatibility attributes (e.g. data rate) which cannot be accommodated.
Hangup Cause Code Table - FreeSWITCH - Confluence
Description