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(IPT, Internet Telephony) Use of IP dataconnections to exchange voice and fax data that havetraditionally been carried over the public switched telephonenetwork.During the late 1990s, an increasing number of telephone callshave been routed over the Internet. Calls made in this wayavoid PSTN charges. Unlike traditional telephony, IPtelephony is relatively unregulated.Companies providing these services are known as InternetTelephony Service Providers (ITSPs). They include telephonecompanies, cable TV companies and Internet Service Providers(ISPs).There are still many problems with voice quality, latency,compression algorithms, and quality of service.Voice over IP is an organised effort to standardise IPtelephony.See also Computer Telephone Integration.Internet Telephony Overview(http://fokus.gmd.de/research/cc/glone/projects/ipt/).