Hello, sorry for my bad english. Simply, I have provider Telekomaustria for VoIP lines. When I use some software VoIP client like X-lite, there is not problem with connectivity to this provider (from the same computer where is 3CX central installed). But I cant to setup the same parameters of VoIP line in 3CX central. Why?... For example in X-Lite there are 5 parameters to configure VoIP line: - Display Name, - User name, - Password, - Authorization user name, - and Domain But in 3CX central there are completly only 4 parameters to configure VoIP line: To configure my VoIP provider: - Registrar/proxy + outbound proxy (that's two parameters but for my problem it's the same like Domain in VoIP client) To configure VoIP line: - External number - Authentication ID/user name - Password The provider Telekomaustria had different User name and Authentication ID, so this two items cannot be fill only in one field. Where can I find the field for specify what is stored in field "Authentication ID/user name" and the field for input the second item?? I supposed that solution is in change items in headers for outbound/inbound communication with provider, but is it? And specifically, how should i do it? Thanks you very much for your help!