Hi thanks for your reply...but for SIP built in N900 there are different options. the fields sre bit different than what it mentioned on Jumblo Website. The fields mentioned are: 1. Address : sip.address@example.com (just an example as shown 2. password: 3. Use for telephone numbers Checkbox 4. outbound proxy 5. port : 5060 (this is ok) Please advice what to fil in the above cloumns