proxy among a cluster of controllers is a mechanism for orchestrating the communication between the controllers within a cluster to increase the efficiency of transmitting multicast streams to client devices connected to the cluster of controllers when multiple client devices are connected to a cluster of controllers and are subscribed to one or more of the same multicast groups it is desirable to avoid transmitting multiple copies of each multicast stream over the network referring to fig9 a a diagram of an exemplary network system including a multicast router is illustrated a cluster of controllers 925 includes the controllers 900 910 and 920 each controller communicates with the multicast router 930 the controller 900 serves as the primary controller for the ap 940 and the client device 960 the controller 910 serves as the primary controller for the client device 970 the controller 920 serves as the primary controller for the ap 950 and the client devices 980 and 990 each of the controllers 900 910 and 920 subscribes to one or more multicast streams on behalf of their respective client devices the multicast streams are then forwarded from each controller 900 910 and 920 to the ap 940 with which the client devices 960 970 980 and 990 are associated one issue to consider is that a wireless network is.