3.2.4.4 Handling Server Too Busy

All methods that require a valid session context handle are to be retried if the call fails with RPC status RPC_S_SERVER_TOO_BUSY (0x000006BB). The number of times the client retries and the amount of time the client waits before retrying is based on the pcRetry and pcmsRetryDelay parameters returned on the EcDoConnectEx method, as specified in section 3.1.4.1. The EcDoConnectEx method is the only method that creates a session context handle, so successful processing of this method is a prerequisite for any method that requires a session context handle. For more details about circumstances under which the RPC_S_SERVER_TOO_BUSY status code is returned, see [MS-OXCROPS] section 3.2.4.2.