Legacy Voice and Data Migration

Most incumbent service providers have legacy voice networks and a separate overlay data network The attractiveness of this setup for many carriers was the ability to build a network optimized for data services; but this did very little to address voice network evolution concerns. Thus, most PSTN voice services are still provided using circuit switches with traditional TDM access equipment and most data services are still provided using an overlay network or TDM access (e.g. for dial-up access to Internet). Note: to understand the value of the PurePacket solution for those scenarios where access is already being provided by an Integrated Access Device, see the Access Network Convergence solution.

What does PurePacket™ bring to the evolution of these legacy networks?

PurePacket brings the service provider a circuit-to-packet migration path for TDM access (voice and dial-up data) and an integration solution for access to voice and data networks.

As shown in the network architecture diagram below, PurePacket enables a service provider to migrate TDM access to a next-generation IP/MPLS access infrastructure, and offer voice and data services while utilizing a cost-effective unified access infrastructure. These benefits are accrued because PurePacket is designed as a multi-service access solution.

PurePacketOUTburst® provides the IAD functionality and either a PurePacketNode® or a PurePacketCompact™ provide an access aggregation function. A PurePacketNode is shown in the picture. The difference between the PurePacket solution and an ATM or TDM solution, is that traffic is managed using MPLS Labeled Switch Paths (LSPs) rather than ATM virtual circuits or even dedicated TDM DS0 channels.

PurePacket has been designed and optimized for packet-based access; thus it is more efficient than traditional service provider overlay data networks. The PurePacket access network carries all traffic in packet format without additional cell/frame overhead. This design is also applied to voice services, which are packetized at the IAD.

PurePacket's use of advanced traffic management techniques allow all traffic to be managed to meet service-specific requirements, such as low latency for voice or dedicated bandwidth for dedicated data service application s (eg. Committed Information Rate - CIR).

As can be seen above, PurePacket also provides an integrated VoDSL and Digital Loop Carrier (DLC) function for terminating TDM voice traffic to a Class 5 switch. The advantage of this solution, is that it represents less equipment for a service provider to purchase. In keeping with the multi-service nature of the solution, the PurePacketNode forwards IP traffic onto a service provider's core network where it is routed to the Internet or a Private Network domain.

Completing the portfolio is the PurePacketOMS™ (Operations Management System) that provides a common management system for the entire PurePacket solution, as opposed to multiple management systems commonly associated with multiple product implementations. For a service provider this translates into operations efficiencies in provisioning and configuring network elements as well as delivering new services.

After a next generation access network is deployed, what comes next?

The answer is the ability to leverage this next generation access network with an ongoing evolution of the core network and migration of voice services to a packet solution. This is shown in the network architecture diagram below.

One key aspect of the PurePacket vision is the ongoing evolution of the core network to an MPLS-enabled network. Because an MPLS aware network is Layer 2 protocol independent, this can be built on top of either IP and ATM infrastructures. By utilizing PurePacket, a complete IP/MPLS solution can be deployed, from access to core.

Another key aspect of the PurePacket solution, is its ability to fit within a service provider's evolution path from the circuit switched voice services network (the PSTN) to a SoftSwitch, packet-based voice services infrastructure.

A SoftSwitch architecture can deliver enhanced revenues using a distributed architecture that allows each functional component to scale independently. This scaling ability will enable a service provider to cost effectively introduce enhanced IP services, enter new markets, or implement small- scale deployments. Yet this same architecture will scale to large market sizes and the requirements of larger customers (eg. enterprise) as their demand for services grow.

PurePacket provides next generation access to a SoftSwitch model as easily as it provides next generation access to the circuit-switched model, without equipment forklifts or replacements.