1. Kamailio, Openser, asterisk, a2billing, OpenSIPS, Media proxy, RTP proxy, Elastix server, VICIDIAL Server, FOP, FreePBX & TrixBox etc installation and configuration.2. DID Setup for different provider, Digium, DID callback with asterisk. DID number forwarding to mobile phone or different extensions and Virtual PBX.3. Xlite, web phone, SIP phone implementation with asterisk.4. Asterisk conferencing with at least 10 users at a time IN distributed environment.5. Additional SIP Accounts, auto voicemail, music on hold, Voicemail Customization6. Scheduled conferencing, Calling features.7. Voicemail in Asterisk. Call routing for different provider for different plan.8. Java scripts for java mobiles for balance check, registration, referral program etc.9. Calling Card implementation10. Made Customized IVRs for calling card. Account recharge with vouchers via IVR11. Allow calling from website, call logs, reports, recharge account with different payment options, voucher recharge etc.12 SM