SIP providers are plenty: Sip2Sip, OnSIP, AntiSIP, pbxes, Ekiga, IPtel, Linphone itself, not to mention various SIP-to-PSTN providers like ippi and various Dellmont clones. For pure SIP, I used AntiSIP most.
SIP providers are plenty: Sip2Sip, OnSIP, AntiSIP, pbxes, Ekiga, IPtel, Linphone itself, not to mention various SIP-to-PSTN providers like ippi and various Dellmont clones. For pure SIP, I used AntiSIP most.