One truism of modern networks is that they continue to become more intelligent. Another widespread article of telecom faith is that application-oriented intelligence must be introduced at the network's edges, not into its core traffic-control nodes, such as IP routers and switches. According to the orthodox view, new application functionality springs up more rapidly when the intervening network functions simply as a dumb, general-purpose communications channel.

Oddly, Cisco - the bluest of the blue-chip IP router vendors - seems to be challenging this orthodoxy. Cisco recently announced a new family of products that it claims embed greater intelligence in networks. Under its Application-Oriented Networking (AON) strategy, the vendor plans by year-end to offer content-filtering blades that can be configured into its routers and switches.

Essentially, AON devices are content-aware network appliances. They are important adjuncts to routers, switches and other traditional Layer 3 traffic management nodes, but they're not a new phenomenon in the marketplace.

Actually, the true pioneers in this niche are the Web services management (WSM) vendors, which for the past several years have offered proxies, agents and appliances to filter and control the flow of XML/SOAP traffic in keeping with centrally managed rules and policies. Some WSM vendors specialize in providing performance-optimized, hardware-based, XML-processing appliances. XML appliance vendors DataPower, Sarvega (recently acquired by Intel) and NetScaler (recently acquired by Citrix) offer the closest direct competitors to Cisco's emerging AON family.

So Cisco is not the first mover in the content-filtering appliance niche - not by a long stretch. But you wouldn't know that by reading its marketing materials. The vendor describes AON as the "first network-embedded intelligent message-routing system, integrating application message-level cSo down deep and despite its AON positioning, Cisco isn't really recommending that customers put more application or middleware intelligence into the network backbone. The company is simply recommending that AON blades - which provide this intelligence - be deployed at the network edge.

Cisco's AON positioning seems to hinge on a Cisco-centric notion of what it means for a "message-routing system" to be both "intelligent" and "network-embedded." How does Cisco classify integration brokers and message-oriented middleware, which are deployed into networks, filter application messages, perform policy-driven message routing and possess intelligence? Does "network-embedded" mean, for Cisco, that the message-routing intelligence must be deployed onto traditional Layer 3 platforms, such as routers and switches? Is Cisco urging customers to upgrade traditional routers and switches to newer AON-enabled models that route traffic based on both IP addresses and the contents of XML/SOAP and other middleware messages?