IP Backbone Design for Multimedia Distribution: Architecture and Performance

摘要

Multimedia distribution, especially broadcast TV distribution over an IP network requires high bandwidth combined with tight latency and loss constraints, even under failure conditions. Due to the high bandwidth requirements of broadcast TV distribution, use of IP-based multicast to distribute TV content is needed for efficient use of capacity. The protection and restoration mechanisms currently adopted in IP backbones use either IGP re-convergence or some form of Fast Reroute. The IGP re-convergence mechanism is too slow for real-time multimedia distribution while a drawback of fast reroute is that traffic is re-routed on a link-basis (instead of end-to-end) so there can be traffic overlap during failures. By this we mean traffic passing through the same link along the same direction more than once; this requires more link capacity or it will result in congestion. We propose a routing method that interacts with Fast Reroute and multicast to minimize traffic overlap during failures. We also present an algorithm for link weight setting that avoids traffic overlap due to any single link failure. Performance analysis shows that our methods improve network service availability and significantly reduce the impact of failures.