We have had some reports this week of poor call quality on SIP2SIM some of the time, and it seems to be getting worse. We are looking in to it, and have had reports that it is particularly bad today. It seems to be something in the link between us and the mobile carriers.
Detailed logs have been sent to the carrier and they are investigating the cause of this.
The carrier is making changes soon that may address this issue.
Our carrier implemented a change at their end at around 7pm on Monday which should fix call problems. We are monitoring this ourselves and welcome feedback from customers.
The carriers have made a change which they believe has addressed the issue.