Dear cyrikltd.
I have experiences in Telecom and I worked on telecom company for 5 years.
So I have deep experiences in Linux, Asterisk PBX, 3CX Server,Ozeki systems and libraries and VoIP as well as powersmpp.
As you can see on my profile, my last project was voip project and now completed.
Now I am free and can start your work just now.
Let us talk more about via chats.
Thanks. Bryan