CIRCUIT EMULATION VS. CIRCUIT REPLACEMENT: COMPARING ETHERNET PLUS TDM, TDM OVER IP, AND VOICE OVER IP

摘要

In recent years data traffic has replaced circuit switched voice and TDM leased line services as the predominant traffic on telecom networks. By 2002 the volume of data traffic was double that of voice and increasing 2x every year according to market researcher RHK. As a result telecom service providers have invested in IP Routers, Ethernet Switches and other datacom equipment that has allowed them to move the bulk of data traffic off of then-voice networks and onto more efficient packet networks. While this has relieved the pressure on their voice networks it has left service providers with the difficult and expensive task of supporting separate voice and data networks. The next step is for service providers to move all of their voice and data traffic onto a single, converged Internet Protocol (IP) network. This converged network approach eliminates the redundant cabling, hardware, and administration that are required to operate separate voice and data networks. Service providers will benefit from more efficient use of network resources, lower operating and capital costs, and increased revenue opportunities. In this paper we'll look at three solutions―Voice over IP (VoIP), Ethernet plus TDM (EthernetPlus), and TDM over IP (TDMoIP)―focusing on the different approach each one takes to the problem of combining voice and data traffic on a single network. We'll also look at the pros and cons of each approach and evaluate how well it satisfies the goals of an ideal converged network solution. 1. Does it support all the legacy TDM services provided on circuit switched networks? 2. Does it provide seamless integration with existing TDM protocols and signaling? 3. Does it ensure the same Quality of Service (QoS) as TDM networks? 4. Does it utilize network resources more efficiently? 5. Does it preserve the installed base of PBXs? 6. Does it offer a significant reduction in capital and operational expenses?