Towards highly scalable multicast via explicit path definition

Group communication is a communication pattern where data is distributed from one sender to many receivers. It is widely applied in content distribution scenarios, such as IPTV, live streaming, video conference, data delivery, and others. Multicast is an efficient one-to-many data distribution method. However, application-layer multicast still has problems of inefficient network utilization as it is not allowed to control network elements. Existing network assisted multicast is unable to meet the newly emerging demand, such as multicast traffic engineering and load balancing. Some implementations of network assisted multicast are also limited to scalability issues caused by limitations of per-flow state maintained in network elements. In this paper, we introduce a novel multicast technology called Carrier-Grade Minimalism Multicast (CGMM) which leverages a string of bits, the bitmap, to instruct node to locally duplicate packets and forward them over several links without per-flow state and encapsulates bitmaps as binary in-packet tree for explicit forwarding path.