I am building a call center with initial 60 agents and final 200 agents. 2xE1 are applied for incoming calls. can I use asterisk to build a large scale call center?
Yes you can. You need * and another open source solution called astguiclient astguiclient.sourceforge.net/vicidial.html
The site includes a full install document and like these forums has a very helpful mailing list regularly contributed to by the developers. There is also a very good case study on there which allowed me to get funding from my employer to investigate further.
Highly recommend having a look.