Voip engineer, creating turn-key VOIP platforms for online bussines with WEB-site, Voip billing rates/routes setup, VOIP dialers, mobile dialers, DIDx provider integration, paypal online payments for Calling card business, DID and other.

hire me on UpWork: http://www.upwork.com/o/profiles/users/_~0195c17a170898a757/

I have experience in Asterisk, Sysmaster/VoiceMaster brands (http://sysmaster.com).
iTelBilling, iTelByteSaver, iTelSwitch, Billbery, Mera MVTS, a2billing, freepbx, opensips, kamailio