1.logon by using admin account,
2. then 'advance'
3. choose tab 'Voice'
4. choose line1 if you connect your phone with line 1
5. in group 'Proxy and Registration', check 'Register Expires:', change from a large number (by default) to 120, let your phone re register every 2 minutes
also, make sure
1.logon by using admin account,
2. then 'advance'
3. choose tab 'Voice'
4. choose 'SIP,
5. check last group 'Nat Support Parameters', 'Nat Keep Alive Intvl:' should be set as 15
if works for you, pls reply here
2. then 'advance'
3. choose tab 'Voice'
4. choose line1 if you connect your phone with line 1
5. in group 'Proxy and Registration', check 'Register Expires:', change from a large number (by default) to 120, let your phone re register every 2 minutes
also, make sure
1.logon by using admin account,
2. then 'advance'
3. choose tab 'Voice'
4. choose 'SIP,
5. check last group 'Nat Support Parameters', 'Nat Keep Alive Intvl:' should be set as 15
if works for you, pls reply here