Lori MacVittie recently wrote a piece on Cisco's AON in Network Computing.

She raised a couple of questions about peoples' general willingness to do anything that may disrupt what their connectivity-centric network devices are designed to do - primarily switch and route traffic at layers 2 and 3.

  • Extensibility can be a great thing, but network administrators are likely to quash developer-written code on their routers. And therein lies the greatest strength and weakness of AON technology.
  • The risk is that compute-intensive XML parsing and transformations will adversely affect performance of core routing functions. There are fears regarding whether a hung process on an AON blade might force the router to need a reboot, something that is rarely done except on a carefully scheduled basis since it disrupts services across the enterprise.

The discussions that I have had with customers and prospects around the world tend to support the line of thinking that there is a low-level function of ensuring that things are connected to each other.  The higher level functions of manipulating traffic at the application level to improve the performance, security or availability of applications is highly desired but not at the risk of disrupting connectivity.  Therefore, people tend not to be big fans of approaches that consume CPU cycles on routers or switches and potentially degrade the performance of their primary intended function or require operating system changes on those devices in order to support higher level functionality.

What do you think?