The names in the Socket Type column are identifiers that apply to all of the above APIs and do not follow the naming convention for any specific API. These message numbers and codes are in the TCPERRNO.H include file.

When a socket call is processed, both a return code and an error number are returned to your program. If the return code is 0 or a positive number, the call completed normally. If the return code is a negative number, the call did not complete normally and an error number is returned. See the following table for the meaning of the error number that is returned.

For the following error conditions, a name is returned by C socket calls and a number is returned by the sockets extended interface calls. The error condition return codes can originate from the socket application programming interface or from a peer server program.