Now is more than one server client,
To send a the same information for each client to send a, the efficiency is very poor,
Can you send a message, the information contains multiple clients address?

Before also tried multicast multicast, but multicast due to the complexity of the wan environment, there are many did not unlock the function of the router, lead to cannot be used in wan,
Is there any way to send this?

[data]
[the target address 1]
[the target address 2]
[the target address 3]
[the target address 4]