System.Net.WebExceptionStatus
CacheEntryNotFound = 18
ConnectFailure = 2
ConnectionClosed = 8
KeepAliveFailure = 12
Pending = 13
PipelineFailure = 5
ProtocolError = 7
ReceiveFailure = 3
RequestCanceled = 6
SecureChannelFailure = 10
SendFailure = 4
Success = 0
Timeout = 14
TrustFailure = 9
UnknownError = 16