PDF of this tutorialClearly, implementing preswitch off-load via AGW is a major step in the right direction. Preswitch packetization provides even further improvement in off-load and economics, as well as positioning the infrastructure for next-generation converged voice and data.
In terms of economy, packetization at the ingress CO reduces modem transport bandwidth required by a ratio of greater than 6 to 1. This allows the use of this bandwidth for other purposes and extends the life of existing equipment as PSTN tandem trunk and switching capacity is reclaimed through the absence of Internet traffic.
Moreover, preswitch packetization provides the platform for strategic investment in voice off-load. Advancing the all-packet network deep into the line side, new access gateways can be devised to packetize all voice and data preswitch for ultimate off-load, as well as form the foundation for next-generation convergence platforms.
In the carrier-grade convergence solution, voice, modem, and DSL traffic will terminate right on the platform, obviating the need for external DSLAMs and other stand-alone access equipment. GR–303/TR–08 support will make the platform totally transparent to the DLC and the Class-5 switch, while voice will be directly and reliably packetized to VoIP, VoATM (VToA), or VoFR and transported accordingly. Scalability will be improved by eliminating the need to purchase extremely expensive, long lead-time Class-5 and tandem switching equipment.
Figure 11. Preswitch Packetization Off-Loads PSTN and Provides Foundation for Converged Network
In the end, next-generation convergence solutions will allow carriers to save tremendous switch resources by redirecting data access technologies as well as terminating services on a platform that resides before the traditional circuit-switched network. By accomplishing this directly upon a next-generation convergence platform, carriers can lessen their investment in circuit-switching equipment as well as service-specific narrowband and broadband platforms.
