Make optimal path have more capacity.
If your lead time for ordering circuits is <1 day and your cost for excess bandwidth is zero, that's certainly a viable strategy. Most of us, even facilities-based carriers, don't live in that dreamland.
No, it takes me 60 days to get approval to order a circuit which wont be delivered for another 90 days, and somehow I have no problem with it consulting for non-facilities based carriers. The reason for the problem is that there are people at the facilities based carriers that have no interest in saving the money and making their network more flexible, largely due to constant hand-greasing from the sales people those who are selling them equipment to make marginal improvements in their very broken networks. No backbone ever should have congestion inside itself, and no backbone ever gets to control someone else's network. This is the fundamentals of the business case at hand, which cannot and should not be redefined. So figure out how to (a) not have congestion inside the backbone itself (b) not have congestion on the interconnects
Please distinguish between startups desperately marketing OSPF under a trademark, and tier 1 carriers who use _significantly different_ routing strategies and won't even acknowledge it without an NDA.
The problem with tier-1 carriers is that their networks are a mess since too many of them have too many buyers that get too much gooey stuff stuck to their hands for buying overpriced and wrong gear and services.
A carrier can't exercise fine-grained control over what traffic levels their peers/customers/upstreams send them, but it is possible to react in real-time to varying traffic levels and prevent congestion (within your own network) from flash crowds, link outages, peer flaps, etc.
Business case requirement (a) - your internal outages should not cause your backbone links to overflow, especially if you claim to be a tier-1 carrier. If it does, you do not have (a) requirement met, so solving any other issues is a waste of time.
Capcity, even in our current bandwidth glut, is expensive. If you can maintain the same performance level with less capacity, you keep more profits at the end of the day -- and that's the real goal, not design purity.
Rubbish again. Capacity (both longhaul and short haul) and bandwidth is cheap for the companies. However, if the buyers actually push sellers, the sellers won't have a reason to take buyers to Morrimotto's, give them Louis Vuitton handbags and give them SuperBowl tickets. Alex