[SR-Users] How to change contact in SIP INVITE

Hi everyone, I use kamailio and have some problem, need support. My scenario: - Kamailio ( x.x.x.x ) --> SIP provider (y.y.y.y) When i callout, SIP INVITE have 2 Record Route (1 x.x.x.x , 1 127.0.0.1) and 2 Via (1 x.x.x.x , 1 127.0.0.1), SIP provider reject it. I try to enable topos, SIP INVITE now have 1 Record Route x.x.x.x , 1 Via x.x.x.x. Everything look ok but Contact be masked like <sip:abcdefghijk@x.x.x.x> and SIP Provider reject it. Any one know how to have Contact as <sip:0123456789@x.x.x.x> where 0123456789 is our SIP number. Sincerely, ---- TRAN DUC THANH IT Manager ZLINK TECHNOLOGY CO., Ltd Add: 4th Floor, 14 Phao Dai Lang Str, Dong Da Dist., Hanoi, Vietnam 186 Bis Tran Quang Khai, Dist 1, HCM, Vietnam Tel: (84-24) 7 309 99 68 / (84-28) 7309 99 68 Mobile: (84)988612049 - (84)904706808 - Skype ID: thanhtd07 Email: [ mailto:tranthanh@voip.com.vn | tranthanh(a)voip.com.vn ] ZLINK - VoIP Solution - Software Licensing - Server&Network Device [ http://voip.com.vn/ | VoIP.com.vn ] - [ http://azsoft.com/ | AzSoft.com ] - [ http://serverhot.net/ | ServerHot.Net ]