The Latest In Developer Resource Blades: Page 6 of 27

Their work is complimented by that of software makers such as GoAhead Software, who specialize in creating "abstraction layers" facilitating access to system-level HA functionality by application programmers who aren't HA specialists.

FOURTH-GEN BUSES


By the time of CPCI's emergence, it was already obvious that the "telephony bus" paradigm of switching PCM timeslots around a system was backward-looking.

IP telephony was already demonstrating that it was possible to build "telephony" systems whose connections to the PSTN - and timeslot-based digital voice communications - were entirely mediated through a gateway device, which encapsulated all "portwise" synchronous protocol and signal-processing functions. Remaining functionality - switching, content signal-processing, other application services - could be provided asynchronously, using the IP network as a generic transport and switching mechanism.

Even within the "gateway device" - an isolated and increasingly generic network component - it was apparent that asychronous internal resource-to-resource and resource-to-CPU communications would bring significant benefits - easier, more flexible scaling of resources to actual traffic requirements; and overall greater system scales.

In the end, the idea of "packet backplanes" seems to have emerged as a fused vision: the idea of "putting the Internet into the machine," coupled to the more hardware-bound vision governing the emergence of CPCI and the H.110 bus.