Interestingly, some major transoceanic undertakings have begun looking very favorably towards a meshed topology solution, eschewing rings. Verizon is championing this approach at the present time as a consortium partner in the Trans-Pacific Express (TPE) cable laying venture to China, and offers justifications for doing so in several interviews and PPT prezos I've come across. Makes sense. From: http://preview.tinyurl.com/yqcrzm Article "Verizon Business plots business plan for ’07 and beyond" May 2007 Issue of Lightwave Magazine <snip> "Last year, Verizon also took steps to improve the reliability of the transatlantic portion of its global IP network. In the past, traffic moved across the Atlantic over SONET rings, which provided redundant paths. However, such architecture only protects against a single failure in a given ring. A failure or service interruption on two or more segments of the same network required the deployment of a cable ship-the nautical equivalent of the truck roll-to restore service. Today, Verizon Business operates a mesh network, using Ciena CoreDirectors (www.ciena.com), to move traffic between six diverse paths that can be routed onto other undersea networks in the event of a network failure." <snip> Of course, these offerings are still being "productized," so it remains to be seen what terms and conditions they carry, and how they will be priced. Frank == On Fri Jun 22 11:56 , Sean Donelan sent:

On Fri, 22 Jun 2007, Hank Nussbacher wrote:

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Tell that to the 10 gig wave customers who lost service. Very few cable systems provide protection at the 10 gig wave level.

If you don't pay the extra amount for a protected circuit, why should your circuit get protection for free when others have to pay for it? Now, if there are 10G customers with protected circuits who lost service, then hopefully they have in their contract hefty penalty clauses against the carrier. If not, then they are just plain stupid.

Is paying for "protected circuits" actually worth it. Or are you better off just buying two circuits and using both during normal conditions. Use switching at layer 3 to the remaining circuit during abnormal conditions. Most of the time, you get twice the capacity for only twice the price instead of a "protected circuit" where you only get the once the capacity for twice the price.

Of course, there is still the problem some facility provider will "groom" both your circuits on to the same cable. If you are buying pre-emptable circuits, hopefully you understand what that means.