How to call back an internal number?

Question

VoIP

Good time!
Such a situation, there is a Yeastar s300, carried out the simplest setup:
1. Created an outgoing route through the operator's sip
2. Created internal numbers
3. Cut groups of ext. numbers
4. Created an incoming route
5. Assigned group numbers to the input.
And I actually set up the phones, everything is fine, we call the city, we receive calls, etc.
Later, the problem turned out that if you have a missed call from an internal subscriber on your phone, then when you click "call back", the number is dialed in the format [email protected]_address_SIP_provider.
If you dial 2288 with your hands, then the call goes through.
Do not tell me what's the matter? with IP telephony to you)

Answer 1

Colleagues!
I couldn't figure it out, does anyone have an answer?