3.2.5.5.2 Receiving Push Notification UDP Datagrams

Upon receiving a UDP datagram on the callback address that was previously registered by the client by means of the EcRRegisterPushNotification method, as specified in [MS-OXCRPC] section 3.1.4.5, the client MUST verify that the content of the UDP datagram is valid by matching it with the content of the opaque data binary large object (BLOB) that was provided to the server by means of the EcRRegisterPushNotification method. If the content of the UDP datagram is valid, the client SHOULD make EcDoRpcExt2 method calls, as specified in [MS-OXCRPC] section 3.1.4.2, to receive notification details from the server. Otherwise, the client MUST NOT take any actions on the UDP datagram.