Currently I have a Huawei GSM modem connected to FreePBX and I can make calls with it.
Unfortunately, the current configuration only allows one connection at a time
When I use this SIM card in my phone, I can call two different phone numbers and merge the conversation, i.e. I talk to two phone numbers at the same time.
Are there modules, modem or other GSM devices that will allow several connections to be made from one SIM card?