While you’re on a call, you can answer another call, and you can switch between the two calls.
Answer a call on your ATA phone
Your analogue phone (ATA) works just like a Cisco IP phone.
When your analog phone rings, pick up the handset to answer the call.
Answer call waiting on your ATA phone
Perform a hook flash to speak with another caller who is calling you.
You connect to the second caller and put the first caller on hold.
(Optional) To speak with the first caller, perform a hook flash again.
Subsequent hook flashes toggle you between the two callers. You can't create a conference this way.