Thanks for your help,
I did not test italk on a ata but it is working with my philips modem.
The proxy ip is the same as the domain and registrar.
I read on this forum and another that people use voxalot and italk.
I try using italk with zoiper but it doesn' work.
Using italk with voxalot without to be registred is note possible also.
When I m registred, i can receive but not phone.
Thanks