Dear Sir,
We have over 8 years of experience working with asterisk and other open source solutions (vicidial, a2billing, vtiger and sugar CRM). Our professional engineers have installed a lot of asterisk based call centers, made simple asterisk installation and configuration, configured different hardware (Digium, Sangoma). We also constantly provide troubleshooting for asterisk systems, write additional modules for asterisk etc. Our engineers are able to solve any issue with asterisk. If you are interested, please contact us at your convenience. Thanks and regards, VoIP Experts.