Abstract

Recent events such as the tragic events of September 11, 2001, have underscored the importance of survivable networks. CIO organizations today are facing increased pressures to ensure that business interruptions due to network infrastructure failures are minimal, even after catastrophic events. IT organizations will continue to be challenged as predictions show that more data will be created in the next three years than in the entire history of the human race. Seventy-five percent of this data will be rich media requiring protection against failure situations with near real-time recovery following a network disruption.

Business Continuity and Storage Area Networking (SAN) have become synonymous because they are inextricably linked. In the past, consolidation of storage resources has helped reduce IT costs and simplify operations. Moving forward, however, geographic diversity of storage centers will be mandatory to increase survivability of critical business information. This is exemplified by the Homeland Security Act, which specifies distance separation for data backup of important records. Geographic diversification has increased the demand for Storage Area Networking Services in the MAN/WAN and created new business opportunities for telecommunications service providers.

This paper will help carriers and enterprises to assess the options for using optical networking solutions to interconnecting segments of Storage Area Networks (SANs) in dispersed locations. Three SAN transport alternatives are examined in detail: Wavelength transport (using DWDM/CWDM), SONET transport (using Generic Framing Procedure, GFP) and Ethernet transport (using FCIP, iSCSI etc.). Each solution is benchmarked based on cost, service ubiquity, Quality of Service (QoS), latency/performance and ease of adoption by enterprise customers.

The paper concludes by showing that emerging Storage-Over-SONET solutions are the likely solution of choice for medium / large enterprises to interconnect SANs when a small number of storage interfaces are needed per site or where complete node protection is desired (relying on dual ring interworking). In contrast, DWDM/CWDM is shown to be ideally suited for large data center applications and for last mile applications where fiber is scarce. Finally, Storage-over-Ethernet is shown to have the right characteristics to gain traction in small and medium enterprise storage applications and business continuity applications requiring lower QoS.

© 2005 Optical Society of America