FXS series gateways are high-performance gateways developed by DBL Technology. FXS series gateways are equipped with H.323 and SIP protocols. The reliable line detection function minimizes the risk of line failure. The convenient and practical network escape function directly switches to PSTN external lines when the network is disconnected or voip login fails. Under the use of SIP protocol, it can forward the display number of external calls, which is an important function for PBX applications. The powerful echo cancellation algorithm and balanced circuit design minimize line echo. Low-cost, stable and high-performance are synonymous with DBL gateways, which are the preferred products for PBX manufacturers, call centers and system integrators.