Resilient Multicast using Overlays Aravind Srinivasan Suman Banerjee, Ryan Braud, Seungjoon Lee, Bobby Bhattacharjee Background A C Data delivery to a 1 2 group of hosts B D • Network-layer Multicast • Application-layer multicast Overlay Node Failures A B C D E F G H J K L M Overlay Node Failures A B C D E F G H J K L M Overlay Node Failures A B C D E F G H J K L M Overlay Node Failures A Network losses n are transient B C D Overlay node n failures are persistent until E F G H J detected and repaired ~ 10s of seconds n K L M Resilience High delivery ratio Have latency requirements Streaming audio or video applications Solution: Redundant, low-overhead data paths Probabilistic Resilient Multicast Randomized Forwarding n – Handles overlay node failures – Proactive Triggered NAKs n – Handles network losses – Reactive Randomized Forwarding A B C D E F G H J K L M Randomized Forwarding A Each node chooses a few other cross tree edges at random and forwards data with low probability B C D E F G H J K L M