NetworkMonitoring技术对比.docVIP

Network Monitoring技术对比： No network is an island, entire of itself: every network is a piece of an internetwork, a part of the main (with apologies to John Donne, Devotions XVII. Meditation). Although administrators of small-scale networks can monitor local traffic conditions and identify congestion points and performance bottlenecks, very few networks are completely isolated. Overlay networks have recently attracted attention, due to their ability to support applications such as end-system multicast, structured peer-to-peer systems, global event notification, resilient routing, and denial-of-service prevention. Overlay applications exploit the high flexibility, deploy ability, and computing capability of end systems to provide better network services. The rigidity of the Internet architecture makes it extremely difficult to deploy innovative disruptive technologies in the core. This has led to extensive research into overlay and peer-to-peer systems, such as overlay routing and location, application-level multicast, and peer-to-peer file sharing. These systems flexibly choose their communication paths and targets, and thus can benefit from estimation of end-to-end network distances (e.g., latency and loss rate). End-to-end measurement is a common tool for network performance diagnosis, primarily because it can reflect user experience and typically requires minimal support from intervening network elements. However, pinpointing the site of performance degradation from end-to-end measurements is a challenging problem. A Resilient Overlay Network (RON) [1] is an architecture that allows distributed Internet applications to detect and recover from path outages and periods of degraded performance within several seconds, improving over today’s wide-area routing protocols that take at least several minutes to recover. A RON is an application-layer overlay on top of the existing Internet routing substrate. The RON nodes monitor the functioning and quality of the Internet pa