I recently bought an IP phone and a directional WiFi antenna to participate in voice over IP in HamNet.
It was a bit tricky to get normal phone and hamradio working on the same device, but I finally managed to get it running reliably.
My home network uses a Fritzbox router which registers with the normal telephone provider. IP phones can sign in at the Fritzbox and use the usual provider if a coressponding profile is made in advance on the Fritzbox.
I am using an Innovaphone IP222, so for everyone who uses a phone of the same brand, here is what has to be done.
Make sure the network settings are correct and the phone gets an IP.
DHCP is on by default which should be correct in most cases.
Configure User-1 (profile 1) using the configuration details of your phone provider -in my case the user account of the Fritzbox
Assign a function button to switch from phone (User 1) to ham (User 2).
You have to enter the same login data (ham radio sip server and user / number) as in User 2 (profile 2), which we will create in the next step.
Configure User 2 (profile 2) as your ham profile. Enter the login data for the HamNet sip server (user, number, password, server) and do not forget to
uncheck / deactivate encryption.
Assign a function button to switch back from ham radio (User 2) to normal phone (User 1). Enter the login data to your phone provider as entered in User 1.
Assign another function button to renew your registration with the HamNet sip server. I sometimes experienced that the phone lost the connection to the server (time out). Simply reregistering with this button helped.
Enter the number of the ham profile (2) and check the box.
Done.