1,5 line voip sip phone 2, 5 sip registration 3,3 way conference call 4,IP ... ,support PPPOE Skyline 5 Line Voip Phone(sip&H.323)Overview Function1,support 5 sip accounts2,support 3 way conference ... call3,support sip(RFC2543,RFC3261)4,support recording ... *10Mbps/100Mbps9,support G.711 A/U, G.723.1(5.3k,6.3k), G.729A(8K), G.726(16k,24k ...