RpcMgmtSetComTimeout function (rpcdce.h)

The RpcMgmtSetComTimeout function sets the binding-communications time-out value in a binding handle.


RPC_STATUS RpcMgmtSetComTimeout(
  unsigned int       Timeout



Server binding handle whose time-out value is set.


Communications time-out value, from zero to 10. These values are not seconds; they represent a relative amount of time on a scale of zero to 10.

Return value

Value Meaning
The call succeeded.
The binding handle was invalid.
The time-out value was invalid.
This was the wrong kind of binding for the operation.
Note  For a list of valid error codes, see RPC Return Values.


In Windows XP and Windows 2000, during bind the RPC run time uses the shorter of a 15-minute call time-out, and the time-out set using the RpcMgmtSetComTimeout function. In exchanges subsequent to binding, the RPC run time uses only the time-out set in using the RpcMgmtSetComTimeout function. This option is ignored for ncalrpc and ncadg_* protocol sequences.

A client application calls RpcMgmtSetComTimeout to change the communications time-out value for a server binding handle. Depending on the protocol sequence for the specified binding handle, the time-out value acts only as a hint to the RPC run-time library. Each protocol sequence interprets this setting differently; for ncacn_ip_tcp, the value is used to turn on keep-alives for all calls. For example, for ncacn_ip_tcp, setting Timeout to zero instructs RPC to turn on keep-alives if a response isn't received in 60 seconds (the 60 second interval is implementation-specific and subject to change). In this situation, the client call is not timed out as long as the server us running; however, if the server fails or loses its IP address, RPC fails the call. The TCP time-out hint is used during connection establishment, as well as during request/reply exchanges.

Note  Using the TCP time-out hint is the best practice for detecting failed servers.

In Windows XP, keep-alives for a given connection are turned off when the server responds.

For convenience, constants are provided for certain values in the time-out range. For a list of the RPC-defined values that an application can use for the time-out argument, see Binding Time-out Constants.


Minimum supported client Windows 2000 Professional [desktop apps | UWP apps]
Minimum supported server Windows 2000 Server [desktop apps | UWP apps]
Target Platform Windows
Header rpcdce.h (include Rpc.h)
Library Rpcrt4.lib
DLL Rpcrt4.dll

See also