Software-Defined Multicast with P4
The increasing amount of over-the-top (OTT) live streams and the lack of global network layer multicast support poses challenges for a scalable and efficient streaming over the Internet. Content Delivery Networks (CDNs) help by delivering the streams to the edge of almost every Internet Service Provider (ISP) network of the world but usually also end there. From there on, the streams are to be delivered to the clients using IP unicast, although an IP multicast functionality would be desirable to reduce the load on CDN nodes, transit links, and the ISP infrastructure. IP multicast is usually not available due to missing control and management features of the protocol. To tackle this problem, we developed Software-Defined Networking-based cross-layer approach, called Software-Defined Multicast (SDM). SDM is a one-to-many network service with multicast efficiency and unicast packet semantics. SDM has been investigated using OpenFlow-based implementations. We will explore how the P4 protocol can be used to increase the efficiency and flexibility of SDM.