IT-savvy enterprises seek to locate resources where they are most needed, and most economical. They also try to fully utilize existing capacity before adding additional resources. Indeed, most companies would welcome the opportunity to locate storage resources where space and labor are readily available and affordable. Today's SAN technologies often make these goals difficult--if not impossible--to achieve.
Key storage applications such as disk mirroring, backup and recovery are mission-critical for ensuring e-commerce and enterprise continuity. Geographically dispersed companies increasingly seek to deploy these applications remotely over long distances. Moreover, the performance of many of these applications, and mirroring in particular, depend on low-latency networks. Constrained by SAN distance limitations and latency inducing networks, most companies find it difficult to achieve the benefits of cost-effective long distance storage solutions.
The next step in the evolution of storage networking is clear: global storage networks that provide access to stored data regardless of location. Global storage networks will greatly enhance data availability, power critical business and consumer applications and promote the nascent storage outsourcing movement.
Building a global storage network, however, presents more than a few challenges. It requires flexible, open SAN transport devices that connect currently isolated SAN islands over Internet Protocol (IP)-based networks, and carrier networks optimized to carry storage data.
As in most open marketplaces, several camps now compete over protocols and approaches to SAN transport. Multiple protocols - some open, some proprietary - and a diverse range of opinions on the optimal SAN connectivity methods send mixed signals to the IT community. These technology battles ultimately have the potential to deprive end users of the benefits of SAN transport.
An open and inclusive multi-service access approach can solve this problem. Multi-service access is the only way to address the broad range of applications, needs, and technology tools necessary to drive widespread adoption of SAN transport technology. Multi-service access offers the ability to move and to access enterprise data across heterogeneous LAN, MAN (metropolitan area network), and WAN (wide area network) environments.
Transport protocols are critical elements of SAN connectivity. Multi-service access is protocol agnostic. Many industry leaders back the development of open protocols being just forth by the major standard bodies.
Examples include Fibre Channel over IP with the Internet Engineering Task Force and the Fibre Channel Backbone under revision by the National Committee for Information Technology Standards' T11.3 committee. Both proposed standards attempt to develop an open SAN transport protocol.
Vendor-specific approaches also vy for acceptance. These solutions essentially yield a closed system that locks IT managers into a model that may not service all of their needs effectively and offers no protection against technology obsolescence. Vendor-specific protocols add to the market's confusion and IT professionals' reluctance to deploy a solution.
Multi-service access frees IT professionals from being at the mercy of a particular vendor and enables decision making based on need and budget. The application, rather than the vendor, can now drive the connectivity planning. Deploying a variety of open protocols enables IT managers to effectively and efficiently interoperate with other facilities, customers, and suppliers.
The multi-service access concept has long been a fundamental of core networking. This progressive mindset must now be applied to SAN transport, in order for systems engineers to manage constantly escalating storage demands.
Multi-service access offers five clear advantages.
1. Storage applications can drive WAN-link deployment decisions. Only multi-service access guarantees the system engineer is able to maximize applications' performance.
2. Bandwidth can be purchased based on need. This is a critical budgetary saving because WAN connections are a recurring monthly expensive.
3. The multi-service access approach protects existing technology investments. Incremental upgrades in connectivity can be ordered with minimal changes and disruptions to the overall system.
4. Multi-service access is the only approach that ensure enterprise-wide service. Some connections, such as OC-48 and SONET, are not universally available, and additionally, WAN infrastructure varies widely even within single companies.
5. Multi-service access based on open protocols greatly enhances interoperability. As SAN connectivity continues to emerge, the interoperability of equipment from multiple vendors and varying connectivity options is vital.
As the standards associated with multi-service access mature, the ability to locate resources based on need, rather than technical limitations, will become possible, affordable and practical.