For multicasting I heard you can filter out certain address with WSAIoctl (using aSIO_SET_MULTICAST_FILTER as one of the parameters) and using ip_msfilter structire. Has anyone tested this out out, if not, I will be and give feed back once I'm done testing it. There is also a thing called reliable sending and receiving with multicast. I thought that cant be since it uses UDP to send and receive data, but you can create a socket called SOCK_RDM. This is meant to be a reliable datagram provider. Has anyone used this or tested it, to know that it actually works? thanks

OK realised that the WSAIcotl way only filters out the data that's been accepted from the client that has joined that group, it works but not useful for what I need to be done.

So anyway onto Reliable multitasking

ok for the SOCK_RDM to work, you must have the MSMQ (Microsoft Message Queuing ) installed

I hope you understand that those services are significantly higher level than basic sockets, and that they are Windows-only. For reliable message queues, there are a number of different implementations from a number of different vendors; some of them open source and portable.