Quilt: A patchwork of multicast regions

Abstract

Network bottlenecks, firewalls, restrictions on IP Multicast availability and administrative policies have long prevented the use of multicast even where the fit seems obvious. The confusion around multicast poses a problem for large-scale pub/sub-based applications that need blazing speed even across WAN networks. There are a number of multicast protocols, but none is universally available. Thus relatively few applications are able to exploit multicast technology. Here, we present Quilt, a system that automatically weaves a patchwork of multicast regions each running different protocols, creating an efficient and scalable wide-area overlay. By dynamically exploring the environment at and between end-hosts, Quilt clusters nodes into patches, selecting the best multicast protocol from a developer-provided set on a patch-by-patch basis and adapting as needed. Quilt orchestrates inter-patch forwarding to maximize reliability while minimizing duplication. This paper discusses and then evaluates the system. We find that Quilt is an effective, backwards compatible option for supporting multicast wide-area networks. © 2010 ACM.