Our company uses a SIP provider for telephony, we have SIP clients on iPhones, Computers, Software Apps etc.

Now I want to configure ZOHO CRM so that ZOHO will also act as SIP client: make and receive calls, make notes of when somebody called, etc.

What do I have to do?
Our SIP provider just uses the standard SIP protocol. 

So I need a bridge or something like that.

Why is this so complicated? I don't find anything about how to make ZOHO CRM act as simple SIP client.