The DSLAM dilemma

Abstract

The deployment of DSL (digital subscriber line) technologies worldwide has resulted in complex silicon integration challenges. These issues centre on whether it makes sense to integrate the digital signal processor (DSP) and network processor unit (NPU) in DSLAM (DSL access multiplexer) equipment into a single chip. So far, these two types of functions have not been typically combined on the same chip, and it is unlikely that such integration will be economically sensible in the near future. Memory-, processor- and bandwidth-intensive real-time multimedia are being delivered over IP connections, but standards for multimedia content and methods of delivering it reliably and with sufficient quality of service are in a state of transition. This means that, as soon as a single standard changes, a chip that integrates NPU and DSP functionalities must be replaced, even when the updated standard applies to only one of the functions. Rather than focusing on the integration of DSP and NPU functions onto the same integrated circuit, a more cost-effective solution is to add functions to the NPU that improve the quality and reliability of the services that are becoming more common (such as voice over IP, IP television and online gaming).