申请ipkall ,what is SIP Phone Number and sip Proxy

我上午认真学习了Fitwxc 大侠的文件, 才知道:Googlevoice>>ipkall>>Voipdiscount 是最好的组合, 就申请IPKALL 帐户,SIP Phone Number and sip Proxy 是不是填我的VOIPDISCOUNT 的名字和SIP>VOIPDISCOUNT.COM?
我是use ATT DSL 2wires Gateway modem/router, I did port forwarding firewall:
port 5000-5500 for UDP and TCP
Port 10000-20000 fro UDP
我的不搏号拿电话是没有声音的, 我用手机打GV 的号(should forward my sipgate's phone but 我的SIPGATE的不饷,怎麽办?