Multicast Multilayer Switching (MMLS) provides high-performance hardware-based Layer 3 switching of IP multicast traffic. MMLS switches IP multicast data packet flows between IP subnets using advanced application-specific integrated circuit (ASIC) switching hardware, offloading processor-intensive multicast packet routing from network routers.
The packet forwarding function is undertaken by the switch whenever a supported path exists between a source and members of a multicast group. Packets that do not have a supported path to reach their destinations are still forwarded in software by routers. Protocol Independent Multicast (PIM) is used for route determination.