3.2.5.5.1 Sending and Receiving EcDoAsyncWaitEx Method Calls

When a call to the EcDoAsyncWaitEx method completes, as specified in [MS-OXCRPC] section 3.3.4.1, the client MUST examine its return value and the value of the pulFlagsOut field. If the return value is 0x00000000 and bit 0x00000001 is set in the pulFlagsOut field, the client SHOULD make EcDoRpcExt2 method calls, as specified in [MS-OXCRPC] section 3.1.4.2, to receive notification details from the server. After the successful results of the EcDoAsyncWaitEx method call are processed, the client SHOULD make another EcDoAsyncWaitEx method call to continue to listen for more notifications.

If the EcDoAsyncWaitEx method returns a non-zero result code, it indicates that an error occurred. In this case, the client SHOULD NOT retry an EcDoAsyncWaitEx method call, and SHOULD instead use the push notification method specified in section 3.2.4.4. If the push notification method is not supported, the client SHOULD instead use the polling method specified in section 3.2.4.5.