4452d530_able___FreeSWITCH___Confluence__Description
[ITU-T Q.850 Code] 102 [SIP Equiv.] 504 [Enumeration] RECOVERY_ON_TIMER_EXPIRE [Cause] recovery on timer expiry [Q.850] [Description] 
This cause indicates that a procedure has been initiated by the expiration of a timer in association with error handling procedures. This is often associated with NAT problems. Ensure that "NAT Mapping Enable" is turned on in your ATA. If it is not NAT related it can sometimes be provider related, make sure to ensure another outbound provider does not solve the problem. FreeSWITCH also returns this when the remote party sends a 408 for call expired.
Hangup Cause Code Table - FreeSWITCH - Confluence
Description