Most carriers are now delivering multiple types of services and applications for customers, or if not now, have plans to do so shortly, and the vast majority of these services are being delivered over IP. Many of these services, such as IPTV or videoconferencing, have bandwidth needs that are much more intensive than that of voice, so that the IP transport networks are increasingly dwarfing TDM infrastructure.

Size has further advantages for the IP marketplace. The per-port cost for VoIP over TDM is already much lower, but unlike TDM equipment manufacturers, IP equipment providers are continuing to focus on decreasing the per-port costs of their solutions.

As equipment providers continue to innovate, the gap in per-port cost between IP and TDM will only increase, offering further incentives for carriers to hasten the transition to IP.