More important, but often ignored, are the business issues for using Internet telephony in our daily lives. Just being able to make a telephone call across an IP network doesn't make it practical for all calls. To succeed in the marketplace, IP telephony services must satisfy regulatory, technical, and business conditions. Most households and small businesses are consumers of switched long-distance services. They change long-distance providers according to whoever offers the best deal.
Access charges are a subsidy that let local phone companies offer local service at reasonable rates.
The details of transferring a call between an IP network and the PSTN are not trivial. Current gateways allow the physical handoff of a call between IP networks, but the call has to be logically connected from one network to another. When signaling is coordinated and calls can pass between the PSTN and an IP network, it becomes possible to enable traditional PSTN functions and applications to work with the IP network. Billing presents a challenge for IP telephony providers because there are no standards yet. Once the technical details are resolved, the networks connected, and the access charges assessed, it will be difficult to tell Internet telephony from the real thing.