VoIP Software

Historically, VoIP Software focused mainly on the DSP, primarily due to the components’ high representation in the design of VoIP platforms. Not surprisingly, OEMs centered their design decisions on which DSP they intended to use, with the standard considerations of performance, size, and power dissipation following suit.

The VoIP Software vendors responded in kind by supplying the necessary codecs and data packaging components necessary to run on the DSP, however this bottom-up approach left manufacturers to fend for themselves with the most critical design elements, including system management, signaling, call control, gateway control, and control plane interface. Often, the integration of these disparate components was quite a difficult process, requiring the stitching together of algorithms and protocols from many different suppliers for VoIP Software. Consequently, system efficiency was sub-optimal, and time to market was painfully slow.

Legacy VoIP offerings also made it difficult for OEMs to incorporate their own intellectual property, such as a battle-hardened echo cancellation algorithm, and since the bulk of VoIP Software was written in hand-optimized assembly, portability across a spectrum of available silicon was not attainable. Without any abstraction in the VoIP Software separating it from the underlying hardware, incorporating next-generation DSPs into the VoIP platform resulted in a complete redesign of the system, further exacerbating time to market and fostering reluctance by the OEMs to embrace emerging silicon products.

The New Top-Down Approach: A top-down architectural approach to VoIP Software, by comparison, utilizes a modular framework to anchor the functions needed in the gateway. Each embedded microprocessor employs its own software engine responsible for specific tasks in the system, i.e., signaling, packet processing, system management and control, etc. To give the entire framework elasticity and ensure that data transfer efficiency is not sacrificed, the individual software engines are linked together by a portable transport mechanism that can be overlaid onto Ethernet, cPCI, RapidIO, or proprietary interfaces.

The media-handling algorithms themselves — vocoders, echo cancellers, tone detection/generation, and the like — are treated as modules that can be added or dropped from the framework as necessary. The framework recognizes the modules through an application programmable interface (API), which the OEMs would adopt to help implement their own repository of intellectual property. By architecting VoIP Software in this fashion, the entire system maintains consistency and robustness and can accommodate evolving standards from ETSI, 3GPP, and the ITU with relative ease.