Call a callback method on WCF server wihout waiting client must finish

I am using two-ways WCF model.

WCF server can send a data (broadcast) to WCF clients using callback method. However server must wait clients to finish the this method. With a开发者_运维知识库 lot of clients, server must wait a lot time. Please help me how to fix this problem at server side so that server mustn't wait clients. Thanks.

Mark the callback method as oneway:

[ServiceContract]
interface IMyContract
{
   [OperationContract(IsOneWay = true)]
   void MyMethod()
}