Tunneling multicast traffic through non-multicast-aware networks and encryption devices

Multicast-based applications, such as collaborative tools and video streaming, are being deployed to the field today. Current strategic and deployed military networks are not designed or configured to support multicast traffic. Furthermore, many security devices such as Virtual Private Network (VPN) devices and Motorola's Network Encryption System (NES) do not natively support multicast traffic. For the Joint Expeditionary Force Experiments, we needed an architecture that would enable the flow of multicast traffic through several encryption devices and across a non-multicast-aware wide area network. This was accomplished through the use of Generic Routing Encapsulation (GRE) tunnels. We developed a solution that allowed dynamic routing of multicast traffic throughout the network. In addition, this solution significantly simplified the configuration of the VPNs and NESs. This paper discusses our dynamically routed, multicast-tunneling architecture and its benefits.