This is Sam from Draytek Crop.
We have a IPPBX device with iptel for SIP account as below.
User B dial to IPPBX could heart the answer from Auto Attendant of IPPBX.
Then user B cannot heart anything (after input the extension of user A) when user A pickup his telephone .
At this momemt, user A could hear everything from user B.
This Network Architecture worked fine before.
And it still works fine now if we select the account of "draytel.org".
Please show us how to solve the problem.
Best Regards,
Sam Hu