What is a SIP trunk you ask? The simple answer is a SIP trunk is a concurrent call that is routed over the IP backbone of a carrier using VoIP technology. They are used in conjunction with an IP-PBX and are thought of as replacements for traditional T1 / PRI circuits and POTS lines. The popularity of SIP trunks has exploded due to their lower cost when compared to traditional phone lines. SIP Trunks are cheaper than analog circuits while maintaining the same service quality that businesses expect from line quality. SIP Trunks cost approximately $20 to $30 per trunk, versus $40 per analog circuit. In addition, long distance termination charges associated with SIP Trunks are much cheaper than traditional analog or TDM rates. AltiGen has certified a number of SIP trunk providers with the MAXCS. We here at Tel-Net use SIP trunks from Bandwidth.com and have been very impressed in the quality and reliability of calls. For more information contact us today.