13:52 Update:
I'm still waiting for the support to call me back and in the meantime I resolved the issue.
It seems that they are migrating batch of users and when you're migrated to the new system the old trunk stops working and the SIP credential page changes to a new one that is not sending the password via SMS but let's you set It
If you're using something like 3CX you need to use a trunk with "Optional 3-way authentication ID" enabled, when before you could use a normal trunk too.
Anyway the correct settings are:
Main Trunk Number: +41XXXXXXXXX
Authentication ID (SIP User ID): +41XXXXXXXXX
Authentication password: THE PASSWORD YOU ARE SETTING
3 way authentication password: THE NEW SIP USERNAME
Registrar/Server: voip.swisscom.ch Port: 5060
Outbound Proxy: fs1.voip.swisscom.ch Port: 5060
I hope this is helping :-)
Giuseppe
