I have 15 years experience with opensource, network, Linux and VoIP systems. I worked in many projects and consulting with Asterisk, FreePBX, Elastix, OpenSIPS, Kamailio, FreeSwitch, FusionPBX, pure SIP RFC3261, integrations with CISCO Callmanager Express.
Integrations with PSTN via SIP, E1 ISDN or MFCr2 , Analog ports, DAHDI techology, RedFone and many others players like Grandstream, Yealink, Digium, Sangoma etc.
I work as analyst in Gnovit Tecnology in Brazil.