Freeswitch Developer

Job Opening: FreeSWITCH Developer

Location: Ecospace Business Park, Rajarhat, Newtown, Kolkata

Employment Type: Full-Time, Permanent

Shift: Day Shift

Experience: Minimum 4+ years in FreeSWITCH/VoIP Development

Responsibilities:

• Design, develop, deploy, troubleshoot, and maintain tools and services supporting our cloud telephony network.
• Customize FreeSWITCH for large-scale audio/video conferencing (1000–1500 concurrent calls).
• Expertise in SIP, RTP, RTCP, TURN, STUN, NAT, TLS.
• Hands-on experience with RTP Proxy and routed audio conferences.
• Understanding of SDP Protocol offer/answer mechanism.
• Work with load testing tools for FreeSWITCH audio conferences.
• Deploy and manage multiple FreeSWITCH instances using load balancers.
• Debug issues using packet captures (Wireshark/Ngrep).
• Collaborate with mobile/API teams for integration and support.
• Knowledge of codecs (PCMU, PCMA, G729, Opus) and open-source telephony technologies (FreeSWITCH, WebRTC).
• Familiarity with SIP servers (SER/OpenSER), proxy servers, SBC, SIPX is a plus.

Qualifications:

• Bachelor’s degree in Engineering (B.Tech/MCA).
• 4+ years of hands-on experience in FreeSWITCH development or related VoIP technologies.
• Strong knowledge of Linux environments and command-line tools.
• Basic to intermediate SQL knowledge.
• Proficiency in scripting (Bash, Python, Perl) for automation.
• Strong understanding of VoIP protocols (SIP, RTP), networking principles (TCP/IP, DNS, DHCP, routing protocols).
• Excellent troubleshooting skills with ability to resolve complex technical issues.
• Strong problem-solving, communication, and collaboration skills.

Industry Preference:

• Travel (Preferred)
• Any Industry (Required)