Vol. 7 No. 3 – April 2009


Fighting Physics: A Tough Battle:
Thinking of doing IPC over the long haul? Think again. The laws of physics say you’re hosed.

Over the past several years, SaaS (software as a service) has become an attractive option for companies looking to save money and simplify their computing infrastructures. SaaS is an interesting group of techniques for moving computing from the desktop to the cloud; however, as it grows in popularity, engineers should be aware of some of the fundamental limitations they face when developing these kinds of distributed applications - in particular, the finite speed of light.

by Jonathan M. Smith

Network Front-end Processors, Yet Again:
The history of NFE processors sheds light on the tradeoffs involved in designing network stack software.

The history of the NFE (network front-end) processor, currently best known as a TOE (TCP offload engine), extends all the way back to the Arpanet IMP (interface message processor) and possibly before. The notion is beguilingly simple: partition the work of executing communications protocols from the work of executing the "applications" that require the services of those protocols. That way, the applications and the network machinery can achieve maximum performance and efficiency, possibly taking advantage of special hardware performance assistance. While this looks utterly compelling on the whiteboard, architectural and implementation realities intrude, often with considerable force.

by Mike O'Dell

All-Optical Computing and All-Optical Networks are Dead:
Anxiously awaiting the arrival of all-optical computing? Don’t hold your breath.

We’re a venture capitalist and a communications researcher, and we come bearing bad news: optical computers and all-optical networks aren’t going to happen anytime soon. All those well-intentioned stories about computers operating at the speed of light, computers that would free us from Internet delays and relieve us from the tyranny of slow and hot electronic devices were, alas, overoptimistic. We won’t be computing or routing at the speed of light anytime soon. (In truth, we probably should have told you this about two years ago, but we only recently met, compared notes, and realized our experiences were consistent.)

by Charles Beeler, Craig Partridge