ErrAccessViolation
ErrAllocationExceeded
ErrFileAlreadyExists
ErrFileNotFound
ErrIllegalOperation
ErrNoSuchUser
ErrOptionNegotiationFailed
ErrUndefined
ErrUnknownTransferID
sBlockSize
sTransferSize
TFTP_ACK
TFTP_DATA
TFTP_ERROR
TFTP_OACK
TFTP_RRQ
TFTP_WRQ