Listen to users conversations

we have a lan network (call center), and our computers work with the Firefly softphone.(IAX mode)
Every person in the network have a username and a password.
Is there a solution for me (supervisor) to listen to conversations between one televendor and a client ?
It told me that there is a way by entering the username 4000 in my firefly and to call the televendor username in firefly but it dont work.

I need your help and sorry for my poor english.

i’ve found the solution :smile:

so you must type 999 and the number of the client :smiling_imp: