One of the truisms of modern networks is that they’re growing inexorably more “intelligent.” Another widespread article of telecommunications 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 communication 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 will, by the end of this year, begin to offer content-filtering blades that can be configured into its routers and switches. Cisco’s AON blades will handle application and middleware functionality, such as the ability to route, transform, cache, compress, track, and apply security and other policies to XML documents and other protocol payloads.
Essentially, AON devices are content-aware network appliances. They are important adjuncts to routers, switches, and other traditional layer-three traffic management nodes, but they are not a new phenomenon in the marketplace. Cisco’s bold AON positioning can’t hide the fact that it’s essentially pursuing a defensive, me-too strategy. When Cisco finally announced these products earlier this year, many of its traditional rivals—such as Juniper and F5 Networks--had long since beaten it to this growing niche.
Actually, the true pioneers in this niche are the Web services management (WSM) vendors, who, for the past several years, have been offering proxies, agents, and appliances to filter and control the flow of XML/SOAP traffic in keeping with centrally managed rules and policies. In the WSM space, some vendors specialize in providing performance-optimized, hardware-based XML-processing appliances. XML appliance vendors such as DataPower, Sarvega (recently acquired by Intel), and NetScaler (recently acquired by Citrix) represent the closest direct competitors to Cisco’s emerging AON family.
So, Cisco is not the first mover in 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 communication, visibility, and security.”
This is classic vendor self-aggrandizement, designed to create the appearance of leadership when the reality is the opposite.
One of the first things that you notice about Cisco’s AON positioning is that it 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-three platforms such as routers and switches?
Could it be that Cisco is urging customers to upgrade traditional routers and switches to newer AON-enabled models that route traffic based both on IP addresses and on the contents of XML/SOAP and other middleware messages?
Not really. Cisco’s not telling customers that IP routers and switches are obsolete. It’s not integrating AON technology into the core of its existing layer-three devices. And it certainly isn’t recommending that customers do application-layer filtering of all IP packets in all routers on the network backbone. That would create a massive performance hit on all traffic.
So, 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: as proxies, gateways, co-processors, and branch-office routers.
In other words, Cisco AON—for all its promise--isn’t a revolutionary product strategy or architecture. It isn’t challenging the orthodox industry view on the appropriate deployment of application and middleware intelligence in the network. And it isn’t expected to cannibalize or replace Cisco’s traditional market for IP routers and switches.
Nevertheless, Cisco’s AON strategy validates and gives greater visibility to a market that’s been emerging for several years: XML-aware network appliances. Cisco’s move into this market signals a growing trend: the core IP router network is evolving to embrace more content-aware XML/SOAP filtering, routing, and traffic management functions, which are provided by specialized appliances.
These are the specialized roles into which network managers should consider deploying Cisco AON appliances and similar devices from rival vendors.