PDF of this tutorialDefinition
The remote access server (RAS) platform is the foundation on which Internet service providers (ISP) and other telecommunications carriers are bringing to market integrated, Internet-based versions of traditional services such as voice over IP (VoIP), fax over IP (FoIP), and data over IP. As the numbers of Internet users grows and as networking technology advances, these services are being successfully marketed as alternatives to those services offered by traditional providers. In addition to voice and fax for consumers, small offices, and telecommuters, these services include virtual private networks (VPN) for enterprises with many mobile employees or small branch offices.
RASs play a key role in the proliferation of these Internet-based services, which represent a significant expansion for the role of RAS platforms from their early use solely as data connections for individuals. Driven by these compelling market conditions, a new universal port–enabled generation of RAS equipment has emerged that provides the ability to support voice, fax, and modem services over nearly any packet-switched network.
Overview
The following tutorial discusses the evolution of the RAS to a universal port-enabled platform. A discussion of current equipment is complemented with a discussion of the next-generation RAS platform, which includes such technical particulars as channel density, power consumption, and processing capability. The concept of the universal port is presented, including explanation of architecture, implementation challenges, and features such as the DSP–based embedded software, which enables the platform's voice-, fax-, and data-over–IP functionality.
