Intelligent Tests for Optical Designs
[FAC: This article from Communications Systems Design gives a good view of the nature of evolving optical networking protocols and platforms. Some good diagrams contained as well. For the full article with graphics, go to:
csdmag.com ]
The first several paragraphs follow:
Optical comm engineers can learn a few tricks from standard routing and signaling tests when working with fast switch fabrics.
By Cary Wright
Communication Systems Design
(07/01/01, 04:51:55 PM EDT)
Today's SONET/SDH-based networks provide high levels of reliability founded on mature and stable technologies. However, these networks are not poised to meet the demands of the impending bandwidth revolution. Deployment of high-speed last mile access technologies such as xDSL, passive optical networking (PON), and cable modems has placed pressure on access routers. Improvements in speed and density of access routers, in turn, place pressure on Internet backbone elements including core IP routers and long-haul optical backbone networks.
This oscillating cycle has made it difficult for communication systems designers to create any kind of equilibrium. When problems are solved in the core, pressure is again applied to develop higher speed and higher density access technologies.
Today's optical network architectures based on SONET/SDH consist of access and aggregation facilities that provide connectivity from a customer's local premises into a high-speed transport backbone (see Figure 1). This backbone is built on SONET/SDH rings, linking metropolitan nodes, and also interconnecting metropolitan regions. A typical trans-continental communication link may consist of many SONET/SDH segments, each a segment of a local ring, all joined to form an end-to-end path.
While technologies such as dense wavelength division multiplexing (DWDM) have relieved immediate bandwidth shortages, issues related to today's SONET/SDH architecture, management, and efficiency are growing increasingly problematic. Provisioning paths through SONET/SDH networks, currently a manual and time-consuming process, is a slow and costly process for carriers. The increasing growth of the Internet and related applications is placing new pressures on optical transport networks, creating path provisioning and management challenges, and bringing with it an increased need for sophisticated protocols that provide the intelligence for fast, scalable and self managed networks. Continued at the above url. |
