TABLE OF CONTENTS In terms of network design and topology, service providers are considering deploying metro GigE in either a mesh, ring, or a hybrid combination of these two models.
With growth in data driving changes in network traffic, service providers are once again evaluating their network architectures. They re weighing one option against another to ensure the right choice for themselves and their customers. At the core of the debate is the role of ring versus mesh topologies in the emerging metro area architecture.
Through the 1990s, rings were the preferred topology in the access network (local loop). That s not likely to change, even with the advent of new data services. This is partially because access traffic is generally headed to a CO or service POP and little connectivity is required among local sites. In addition, SONET/SDH ring protection techniques are perfect for the geographic limits and traffic patterns typical of the metro environment. Most importantly, the local loop suffers from limited fiber capacity with right of ways that are hard to come by. It s extremely expensive to add another path into or out of a facility. Rings are still the most cost-effective strategy for distributing services in densely populated regions like the local loop.
SONET/SDH rings are still being deployed in today s metro core. However, mesh topologies have proven extremely cost effective for carriers building out new IP/packet services. With the huge growth of data traffic, it makes sense for carriers to...
