Embodiments disclosed herein provide advantageous methods and systems that use multicast communications via unreliable datagrams sent on a protected traffic class. These methods and systems provide effectively reliable multicast delivery while avoiding the overhead associated with point-to-point protocols. Rather than an exponential scaling of point-to-point connections (with expensive setup and teardown of the connections), the traffic from one server is bounded by linear scaling of multicast groups. In addition, the multicast rendezvous disclosed herein creates an edge-managed flow control that accounts for the dynamic state of the storage servers in the cluster, without needing centralized control, management or maintenance of state. This traffic shaping avoids the loss of data due to congestion during sustained oversubscription. Other embodiments, aspects and features are also disclosed.