A method is provided, in a server, operatively connectable to a client via a data connection, a method of sending a data stream to the client. The method comprises receiving from the client, a request for data, the request comprising a communication identifier, obtaining a first part of the data stream from a streaming source for sending to the client and sending, to the client, a streaming data message. The streaming data message comprises: the first part, the communication identifier, and a stream indicator, indicating a second data message may follow, comprising a second part of the data stream. The method does not comprise resending the streaming data message if no acknowledgement of receipt has been received from the client. Also a method in a client is provided, as well as the server and the client.