Optical networking. A multi-service global carrier's view

Customer needs are driving AT&T's implementation of optical networking in its core transport network. To stay ahead of explosive capacity demands, AT&T is deploying ultra-capacity DWDM systems capable of supporting 160-400 Gb/s today and more than 1 Tb/s in the near future. AT&T is supplementing DWDM deployment with the deployment of new fiber on selected cross sections to reap the full cost/capacity benefits of OC192 and, in the future, OC768 transport. To terminate the accumulation of optical impairments and facilitate interoperability of technologies from multiple vendors, AT&T is bounding DWDM systems with transponders. The initial deployment of the optical layer network is based on SONET framing and optical-to-electrical conversion for regeneration, cross-connections and restoration.