Vadim, we recognize, and appreciate your concerns. Two major points with regard to the PathControl product, and it's impact on the BGP environments: 1) PathControl is currently targeted toward providing optimized egress routes to multihomed enterprises. Our technology is applicable to core routing, but we certainly acknowledge the constraints in that environment are radically different ... 2) We've integrated extensive anti-flapping capabilities into the product, and in addition have user-configurable settings for maximum rate of route change. Given a high rate of changing performance measurements, the box is capable of generating routing decisions at a high rate. Our analysis (and default settings) show that significant performance gains can be realized with a rate of change in typical deployments less than ~100 prefix changes per hour. (And maximum rates can be constrained lower than this, if desired.) cheers -- Sean Vadim Antonov wrote:
Changing routing information depending on traffic is rather dangerous; do they proivide adequate damping so the system does not oscillate? Is such damping guaranteed to work under a wide range of load patterns?
NSFNET experiments with dynamic load balancing come to mind.
Now, if I were an ISP operator I would be very unhappy if someone injects deliberately changing routes into my BGP mesh; while few such customers may be surviuvable (if their systems do not get to "metric-flap"), having many such customers is a sure way to overload core routers' CPUs.
Time to institute MED fixing on customer BGP sessions?
--vadim
On Mon, 20 Aug 2001, Irwin Lazar wrote:
Is anyone out there familiar with a company called "routescience"? I caught the below press release at and wanted to find out if anyone can relay any real-world experiences with their system? It almost sounds like they are using something like a Keynote Systems performance monitoring tool to inject BGP path preference information.
TIA, Irwin
--- ROUTESCIENCE DEVELOPS PLATFORM TO CONTROL BGP INTERNET ROUTING RouteScience, a start-up based in San Mateo, California, unveiled plans for a unique "route controller" platform for optimizing a company's multiple ISP links by providing real-time performance measurements of paths across the Internet to end users. Using these performance metrics and customer preferences for ISP link cost, RouteScience's PathControl platform determines the best ISP path for end-users and can then automatically update the organization's edge routers with the best path routing information. The route performance measurement relies on a patent-pending closed-feedback loop system that does not use pings. Route updates are provided to the edge routers using standard Border Gateway Protocol. A large company with multiple ISPs would use the systems to route traffic to the ISP links that actually deliver the best end-to-end performance. The solution could also be used by a Tier-2/3 service provider to route traffic to multiple backbone carriers depending on cost and real- time performance metrics. The company said default BGP chooses a sub-optimal route 50% - 80% of the time, depending on the number of alternative ISP paths. Of those routes that can be improved, an alternate ISP is on average 2 times faster. RouteScience claims its system provides deep visibility into ISP performance and could fundamentally change network service agreements and pricing by moving control over Internet routing decisions to the network edge. http://www.routescience.com RouteScience, August 20, 2001