F-SIP Trunks (IP Trunks) provide a solid IP to PSTN (Public Switch Telephone Network) connection for a variety of VOIP applications and are the basis of most Freevoice Networks Services.

F-SIP Trunks can be set up as SIP or IAX using the GSM, G.711 (ulaw) or G.729 codecs. Each F-SIP Trunk enable one (1) simultaneous call and can be used with any PBX or as a stand-alone product to enable IP —-> PSTN connectivity. Available in Flat Rate, Unlimited, and Metered options, F-SIP Trunks offer substantial savings and flexibility compared to traditional services.