On 07/02/11 14:25, Jamie Bowden wrote:
It would help if we weren't shipping the routing equivalent of the pre DNS /etc/hosts all over the network (it's automated, but it's still the equivalent). There has to be a better way to handle routing information than what's currently being done. The old voice telephony guys built a system that built SVCs on the fly from any phone in the world to any other phone in the world; it (normally) took less than a second for it to do it between any pair of phones under the NANPA, and only slightly longer for international outside the US and Canada. There have to be things to be learned from there.
Jamie
They did indeed, but they did it by centrally precomputing and then downloading centrally-built routing tables to each exchange, with added statically-configured routing between telco provider domains, and then doing step-by-step call setup, with added load balancing and crankback on the most-favoured links in the static routing table at each stage. All this works fine in a fairly static environment where there are only a few, well-known, and fairly trustworthy officially-endorsed entities involved within each country, and topology changes could be centrally planned. BGP is a hack, but it's a hack that works. I'm not sure how PSTN-style routing could have coped with the explosive growth of the Internet, with its very large number or routing participants with no central planning or central authority to establish trust, and an endlessly-churning routing topology. Still, every good old idea is eventually reinvented, so it may have its time again one day. -- Neil