Convergence or multi-service networking has introduced new services and economic opportunities and is changing the outlook and the buying habit of telecommunications service providers and networking vendors from single vendor products to customer solutions---a network infrastructure composed of multi-vendor products and services, tailored to address the customers' needs or objectives. This new computing or networking environment spurred by emerging technologies and services is forcing equipment vendors, system integrators, and other solution providers to seek to provide their customers with solutions that are designed or engineered for sustainability. This means that the solution must not only look to meet their immediate needs and concerns, but also to economically accommodate emerging or next generation network technologies. The traditional network infrastructure solution approach, which is product and vendor driven focuses more on vendor product line rather than customer business case and requirements. Such approach would not produce sustainable networks. A solution approach that is business case centered, requirements' driven and sustainability constrained is the only approach that will work. However, the task of building sustainable networks---network infrastructure positioned to easily adapt to emerging technologies without complete disruption of clients' services or dismantling of existing telecommunications' base, present design challenges. These challenges include service and protocol flow between network domains (access, edge & core), security interoperability, seamless connectivity, scalability, etc. In this research, I present a three-pronged approach that meet these challenges. The three-pronged approach is based on Solution Design Exploration (SDE), Strategic Design for Sustainability (SDS), and Adaptive Design Engineering (ADE), and is driven by business case analysis and requirements. The approach ensures that the solution (the network infrastructure) direction flow from the business case understanding and requirements. I would give an overview of emerging technologies, highlight the importance of sustainability in the face of changing networking technologies, and outline the shift from traditional networking, to networking convergence and converged communications. I will discuss the challenge of building successful network solutions in a convergence space, point out the shortcomings of a vendor driven approach, and present the three-pronged approach and its advantages in convergence networking era.
