Web-based customer service system with phone client

The scenario I plan to realize is the following:

  1. customers calls hotline
  2. customers enters his customer id
  3. service staff waits on web-application (php, ajax, angularjs, html5) for calls / no software needed but browser
  4. service staff accepts call in browser and uses headphones
  5. service staff gets automatically displayed information for the caller based on the entered customer id

I am new in phone software solutions and asterisk. Can you give me some tips which components I have to use? Maybe there are similar projects I can have a look at.

Thank you very much!