Using VoIP Software Building Blocks A Look At The Choices

VoIP is now beginning to reach the mainstream market, as reflected in a recent IDC study projecting that the number of U.S. subscribers to residential VoIP services will grow from three million in 2005 to 27 million by the end of 2009. To meet this demand, an increasing number of Original Equipment Manufacturers (OEMs) are now developing VoIP-enabled products. In many cases, the expertise of these OEMs is in the areas of data communications, user interface development, or manufacturing — not VoIP. They need to easily and rapidly VoIP-enable their products without having to build their own VoIP capabilities from the ground up.

OEMs have long known about the benefits of merchant silicon. By utilizing application-specific standard products (ASSPs) produced by silicon vendors, OEMs can realize significant cost savings and time-to-market advantages over the alternative of developing equivalent technologies in-house. Today, no OEM would think of beginning the development of a product by kicking off a series of custom silicon development programs to create processors, memory controllers, Ethernet MACs, or UART controllers that are readily available via merchant silicon vendors. However, these same OEMs will regularly take on massive software development efforts to create from scratch the software that drives this silicon.

Fortunately, software exists from a variety of sources that can be leveraged by the OEM in the same way that merchant silicon is leveraged. This “merchant software” provides the same type of benefits that merchant silicon does in terms of reduced development effort, expense and risk. Merchant software is available in the form of software components or as integrated software platforms.

The Software Component Approach
Software components represent a class of merchant software that is readily available to OEMs, and provides a tremendous amount of design flexibility. This class of software is characterized by individual components or building blocks that perform specific functions. Examples of software components would be a G.729AB codec, or an Ethernet driver.

One advantage of the use of software components is that the OEM can leverage the functionality provided by the software without having to develop in-house expertise in the specific functions or invest developer time on the effort to implement and validate the components. Other advantages include the ability to acquire and deploy only the specific set of functionalities that are needed for the system, as well as the ability to integrate these components into an already-existing architecture.

However, the software component approach does have a disadvantage in that there is a given level of effort required to integrate the individual components into the overall product. This integration challenge may be further complicated if the components are sourced from a variety of vendors, each with its own interface methodologies. As additional sources of components are used, the effort required to manage various vendors increases, and there is a greater risk of encountering problems related to the interaction across components from different sources.

Software Platforms
Software platform solutions are another form of merchant software available to OEMs. Software platforms are solutions that incorporate collections of related functionalities, typically provided within an integrated software framework. A software platform solution may provide a full suite of VoIP media processing (multiple audio codecs, tone generation/detection algorithms, echo cancellers, etc.), together with such call control protocols as SIP or H.323 and a framework that integrates these components and presents the user application with a high-level API.

Software platform solutions share with software components the advantage of the OEM not having to learn and develop the base functionality. This allows OEMs to redirect efforts toward the development of features that further differentiate their products from the competition. A significant additional benefit is that the integration of the various functional components has already been performed and validated by the supplier of the software platform. In many development efforts, the integration of individual functional components represents the most significant portion of both development time and risk, so a software platform in which the functional components have been pre-integrated can provide a significant advantage in minimizing these challenges.

The reduced number of vendors that are a part of the solution may also help to minimize the effort in developing and managing the product. A potential drawback of a software platform solution for some OEMs is that a given platform may incorporate more functionality than is required for a specific application. This can be minimized by selecting a solution that is presented as a modular framework, allowing the unneeded components to be scaled out.

Sources Of Merchant Software
OEMs can access merchant software either directly from an individual merchant silicon vendor, from board-level vendors or through third-party software companies. The source of the merchant software adds several other decision factors that must be considered.

Software provided by a merchant silicon vendor has the benefit of being pre-integrated with the specific silicon device being used. This can save integration time and effort with respect to not having to learn the low-level details of the silicon interfaces. Additional benefits from this approach are that the software may (but not necessarily) take full advantage of the silicon architecture, providing possible performance gains. However, it is this same point that can become a disadvantage to the OEM, as the software is almost always limited to use on the specific silicon device. As a result, the provided software is not portable to designs that use silicon from another vendor. Additionally, many merchant silicon vendors will provide software as an enabler of the sale. Software development is not a key focus of the vendor, and as a result timely response to support issues or feature enhancements related to the software may not exist. The completeness and field-robustness of the software provided also may vary greatly across the software offerings from various silicon vendors, ranging from basic lab-grade bring-up or diagnostics code to production-ready solutions.

Board-level solutions — combinations of specific hardware and software — represent another delivery mechanism for merchant software. Benefits of this approach include the reduced development effort both in terms of hardware and software development, as well as integration. The OEM is able to focus on applications development, utilizing the VoIP sub-system provided by the vendor. Because this model takes more of a sub-system approach, it is not appropriate for many designs because the solution is delivered in a specific, defined form-factor. The specific form-factor (PMC module, CompactPCI card, etc.) may not be able to be integrated into the OEM’s target platform, or may require special mechanical or electrical design to accommodate this pre-defined subsystem. The pre-defined nature of a board-level solution may also limit the extent to which new functionality can be deployed at a later time.

Dedicated merchant software vendors represent the final source of merchant software technology. Companies that offer merchant software for both portable and silicon-specific implementations are able to provide an additional level of flexibility to OEMs. Merchant software vendors typically support a number of silicon devices with the same base software components or software platforms. This provides the OEM with the flexibility to make a single investment in learning the software interfaces, and to leverage this investment across a variety of merchant silicon designs. Because the software provider’s focus is on the development and licensing of software, the OEM can be confident that the supplier is focused on the support and continued development of the software technology.

Depending on the specific merchant silicon vendor, and the form in which the software is provided, the advantages provided by this approach can range from meaningful to very significant, especially if the OEM is developing a family of products that would use a number of merchant silicon devices from multiple vendors.

In addition, the software available from some vendors may feature an open architecture that allows developers to easily integrate custom or third-party algorithms, protocols, and control applications into the system. OEMs are thus still able to preserve their investment in their own intellectual property and differentiate themselves in the highly competitive VoIP equipment market. This approach combines all the time-to-market benefits of a turnkey solution with the flexibility of software components.

Time to market for the development of VoIP products has been shortened through the use of merchant silicon. Additional gains can be achieved through the use of merchant software. This merchant software is delivered in several ways, such as software components and software platforms, and can be obtained by an OEM in various manners, from direct distribution with the merchant silicon, as part of a “turn-key” system offering, or from third-party software vendors. Each approach features characteristics that must be considered in relation to the specific requirements of a given product’s development. Utilizing merchant software that provides the greatest flexibility in terms of portability and integration for a particular application, with regard to both the software functional components and the silicon, can reward OEMs with a strategic advantage that enables decreased time-to-market, lower overall product risk and lowered product development costs. IT
Using VoIP Software Building Blocks A Look At The Choices
by Michael Ward