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