Is there an inexpensive and efficient system for incoming calls?

Question

CRM

Recommend an inexpensive and effective system for tracking incoming calls, requests from the site, etc. With the ability to listen to calls. For a large company with branches in the regions. I know about mango

Answer 1

Self-written solution on Asterisk + Web + *sql. well, or analytics of PBX logs,
but in general the question is too extensive

Answer 2

To track calls, there is Ringostat or Calltouch linked to AmoCRM