Having more then decade experience in developing VOIP products. Expertise in following area - 1) Freeswitch development in C / Linux 2) Asterisk development in C / Linux 3) Installation , configuration of PBX (for e.g FreePBX, Vicidial ) 4) Troubleshooting of various VOIP issues like calls , DTMF , audio , fax, system hang, heavy traffic system not working, etc. 5) Comfortable with Freeswitch , Asterisk backend configuration, browsing logs, debugging issues either by logs or by digging into C code. 6) Love to follow proper process whether its development or deployment.