IAD04(W:4S) 4 port VOIP gateway include 4 FXS ports gateway,and with 1 WAN and 1 to ... . IAD04(W:4S) the 4port VOIP gateway includes 4 FXS ports gateway,and with 1 WAN and 1-4 ... FXS;interface: 10/100BASE-T WAN port,1-4 10/100BASE-T LAN ports;1 RS232 port;VoIP protocol: H323 v2,H323 v4,SIP ... interoperatability l Compatiable with voice gateway,IAD,AG,MG devices with H.323 and SIP protocol from l CISCO, ...