Error 0x80EF01F4

Value: -2131820044 | 0x80EF01F4 | 2163147252

What does it mean ?

RTC_E_STATUS_SERVER_INTERNAL_ERROR  
Server Internal Error
Value: 500 | 0x01F4 | 0b0000000111110100

Where does it come from ?

FACILITY_SIP_STATUS_CODE  
SIP - Session Initiation Protocol (VoIP)
Value: 239 | 0x0EF | 0b11101111

Other Errors for FACILITY_SIP_STATUS_CODE