MVC3 AsyncController - Can we send heartbeat data to the client?

[Blizzard]

In order to overcome the (apparent) 4 minute idle connection timeout on the Azure load balancer, it seems necessary to send some data down the pipe to the client every now and again to keep the connection from being regarded as idle.Our controller is set up as an AsyncController, and it fires several different asynchronous methods on other objects, all of which are set up to use IO Completion Ports. Thus, we return from our method immediately, and when the completion packet is processed, IIS hooks back up to the original request so that we can render our View.Is there any way to periodically send a few bytes down the wire in this case? In a "classic" situation, we could have executed the method and then just spun while we waited, sending data every few seconds until the asynchronous method was complete. But, in this situation, the IIS thread is freed to go do other business, and we hook back up to it in our completion callback. What to do? Is this possible?