1,nortel ip phone 2,3-way call,3 Account Number 3,call forward funtion ... with an extremely affordable, incremental investment.HighlightsKey Features: Support SIP 2.0, TCP/UDP/IP, RTP/RTCP, HTTP, ICMP, ARP/RARP ... )Yes1YesSGW-22002 RJ45(LAN/WAN)Yes2Yes nortel ip phone SPH-2100