Error 0x80EF0131

Value: -2131820239 | 0x80EF0131 | 2163147057

What does it mean ?

RTC_E_STATUS_REDIRECT_USE_PROXY  
Use Proxy
Value: 305 | 0x0131 | 0b0000000100110001

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