W60B and W54H can't handle simultaneous calls... Need help

[BobbyfromParis]

Hello,

I set up Yealink W60B and 4 W56H handset with Aircall (VoIP provider) and everything works like a charm, EXCEPT the fact that when an other call is made while one is currently going on, the other handset are not ringing.

Ex : Customer A calls -> All 4 handsets ring, one of them take the call.

Then, while customer A is on the phone, customer B is calling. There is a ring tone for him, like if it was ringing for real on the other side, but unfortunately, everything stays quiet, not a single handset is ringing.

If I end the call with customer A while customer B is still hanging ringing, then all the handset start ringing again. It's the very last step to get my solution working like a charm :-)

Anyone can help ?