Past claims for Internet telephony have proved over optimistic, but the technology remains crucial to the future of the telecoms business. The author reports on how the industry is learning to live with the challenge of network convergence. The development effort required to deliver appropriate QoS levels and seamless interworking with the PSTN has been massive, and is ongoing. Within the closed world of single-company autonomous networks, or the confines of a company WAN/LAN, the technology is now practicable, but it's an open question as to whether VoIP will ever operate across multiple networks with the performance and reliability of the PSTN. Such reservations aside, the operational and service attractions of VoIP will make the successful management of convergence the most important challenge for network operators over the coming decade.