IT-savvy here, but know very little about VoIP.
I have 2 "lines", a VoIP account and a landline. The VoIP line uses an OBi202 ATA with a cordless phone.
I experienced something strange the other day. I used my VoIP connection to call my landline. The landline telephone rang, but I did not hear a ringing sound in the earpiece of the handset attached to the VoIP connection. The ITSP is asking me to Change the SIP port to 5080 and the transport protocol to TCP on the obi device.
Do you think this will help? I don't see what that would change. Wouldn't the symptom I experienced likely be a problem at the VoIP provider's end, and not mine.