... WiFi ,802.11b/g), 1*SIM slot ,PPPoE/ADSL,NAT ,VOIP Ethernet Interface:1-2 *10/100Base-T;Calling Control Protocol ... : Package losing compensation, Dynamic Buffer, Chaos sequence recomposition, voice package high priority, Echo cancellation, Voice Activation Detection, silence restrain and comfort ... customer purview. HIP1860(3) IP Phone SIP PHONE connect with Voip gateway