The emerging service-oriented architecture is introducing better ways to integrate business processes, and business managers are demanding SOA-based applications. These demands for SOA must be balanced with other enterprise network initiatives such as data replication, VOIP and LAN extension. The WAN implications of these emerging applications are profound: exponential increases in traffic volume, more sensitivity to network latency, less predictable traffic patterns and increasing difficulty in identifying high-priority traffic.

In such an environment, there is value in load balancing and prioritising application flows. Application awareness and control belongs at the edge of the LAN, however, not in core network elements. Higher-layer functions best reside on servers and ancillary equipment that are tightly bound to supported applications.

In an on-demand IT world where the performance of critical applications is becoming increasingly more strategic, building application awareness into WANs is a fundamentally flawed approach. Consider these issues:

  • The unnecessary bind. Coupling ever-evolving applications with stable network elements doesn't make economic or operational sense. In grafting the added hardware and software necessary for application awareness onto WAN equipment, users will experience cost and performance penalties as they attempt to optimise WAN architectures based on packet inspection, which potentially increases latency and diminishes throughput for SOA and other enterprise applications.

  • Business flexibility. Pairing network elements and applications hinders organisations from adapting quickly to their fast-changing IT needs. If applications are inextricably linked to WAN elements, IT systems and networks struggle to react swiftly and organisations lose their agility.

  • Operational complexity and cost. Application awareness complicates an IT group's ability to ensure applications are responding to user needs. By taking on tasks traditionally supported by servers and middleware, application-aware elements add to the operational expense of a WAN.

    By contrast, an application-transparent network optimises bandwidth and switches traffic at the lowest possible layer -- leveraging new, flexible optical transport and Ethernet data-switching technologies. This enables the cost-effective creation of networks that provide maximum throughput, inherent security and the lowest latency for each application. Lower-layer, application-transparent networks are very reliable, don't drop packets and deliver a deterministic response. They are scaleable and ideal for high-bandwidth, time-sensitive, mission-critical business processes.

    Organisations need a WAN that is simple, robust, high performing and transparent -- attainable with the flexible optical and data network platforms now available.

    Raghu Ranganathan is technology director in the office of the CTO at Ciena.