1 | Internet is the most widely accessible high-speed PDN suitable for enterprise VPNs. Currently, access to the Internet is available via the PSTN (ISDN, T1, T3). Over time there will be less dependence on the PSTN and more PDN options like Frame Relay and ATM will become available worldwide |
2 | Once the PSTN also converts to ATM in its backbone, voice and data may once again share the same public network infrastructure. VOA standard (Voice over ATM) is under development |
3 | Currently Corporate private data communication networks are based on T1 leased lines or Frame Relay PVCs. The new architecture arises but is not available yet (expected by Y2K): Internet-VPN. In I-VPN the secure traffic can flow not within one enterprise, but among many enterprises and their customers. |