Government agencies and military bases have deployed traditional Add/Drop Multiplexers (ADMs) throughout their networks to offer end-users high-speed OC-12, OC-3, DS3 and DS1 services. With the growth in bandwidth requirements for data, there is a need for deployment of next-generation ADMs that offer Ethernet data interfaces with larger ring bandwidth capabilities.

Challenges

There are two key issues: scalability and Ethernet interoperability. Legacy next-gen ADMs do not scale easily from OC-48 rings to larger OC-192 rings—requiring either a forklift box replacement upgrade or taking the ADM out of service while the OC-48 switch card is physically replaced with an OC-192 switch card. The expensive OC-48 card must then be discarded or placed elsewhere in the network. Additionally, most ADMs that do support Ethernet services do not utilize standards-based GFP SONET mapping. Without GFP, Ethernet services must be converted and reconverted multiple times as the Ethernet service crosses multi-vendor SONET networks. This is also the case with RPR Ethernet solutions.

Solution

Telecom planners and network managers require a single solution that incrementally scales switching capacity, independently of the ring bandwidth size. A "pay as you grow" model more efficiently evolves metro and access networks as demand drives new requirements. Additionally, the universal adoption of GFP for Ethernet mapping to SONET/SDH drives efficiencies by allowing handoff of standard SONET signals across platforms and other SONET networks.

Ciena's offerings

Ciena's CN 3600™ Intelligent Optical Multiservice Switch maintains a distributed switch architecture that grows incrementally as services are added. Growth from OC-12 to OC-48 up to OC-192 is linear and efficient with no wasteful service-impacting central switch matrix card switch-outs. The CN 3600 offers a full array of Ethernet cards from 10/100bT and 100bFX to Gigabit—all supporting standard GFP for transparent transport over any SONET/SDH network, as well as virtual concatenation for aligning service bandwidth to transport bandwidth and LCAS for increasing bandwidth utilization and resilience.

Benefits

• Distributed switch architecture with “pay as you grow” economics
• 30% less capital cost for OC-48 to OC-192 upgrades compared to next-gen ADMs
• 30-40% less capital cost for new OC-192 applications
• Fully interoperable GFP Ethernet services crossing multiple vendor networks
• Distributed VT1.5 and STS switching minimizes ring bandwidth for locally switched services and eliminates CO DCS ports for intra-ring services
• Flexible solution supports additional DCS and International Gateway applications including SDH to SONET service translation