FreeSWITCH Developer /VoIP Engineer

Cerebra; Hyderabad, Pune District, Bengaluru; On-site; INR 1,200,000 - 1,800,000; Full time

Job summary

Cerebra in Hyderabad is seeking a seasoned FreeSWITCH Developer with strong C/C++ and VoIP expertise to design, integrate, and maintain FreeSWITCH-based telephony solutions. You will work on SIP, WebRTC, ESL integrations, and CCaaS platforms to deliver scalable contact center features.

You will configure SIP trunks, RTP/SRTP, NAT traversal, and implement ACD/queue features, call recording, and monitoring while collaborating with cross-functional teams to ensure reliability and performance.

Qualifications

• Hands-on experience with FreeSWITCH development and configuration.
• Strong programming skills in C and C++.
• Good understanding of SIP protocols and SIP trunk configuration.
• Experience with FreeSWITCH dialplans, modules, and ESL/API integrations.
• Knowledge of RTP, SRTP, NAT, codec configuration, and media optimization.
• Hands-on understanding of WebRTC, ICE, STUN/TURN, DTLS-SRTP, SDP, and WSS.
• Experience in troubleshooting VoIP and real-time communication systems.

Responsibilities

• Develop, customize, and maintain FreeSWITCH modules and dialplans using C/C++.
• Implement FreeSWITCH ESL and API integrations.
• Configure and troubleshoot SIP signaling, trunks, RTP/SRTP, NAT traversal, and codecs.

Skills

FreeSWITCH development

C/C++ programming

SIP

VoIP

WebRTC

ESL/API integrations

SIP trunk configuration

RTP/SRTP

Education

B.E./B.Tech in CS/EE/ET/telecom

Tools

FreeSWITCH

mod_callcenter

ESL

Job description

Role & responsibilities

Job Description: FreeSWITCH Developer C/C++ / VoIP Engineer

Experience: 5+ Years
Work Locations: Bangalore, Hyderabad, Kochi, Bhubaneswar, Delhi NCR, Pune
Education: B.E./B.Tech in Computer Science, Electronics, Telecommunications, or equivalent qualification.

Role Overview

We are looking for an experienced FreeSWITCH Developer with strong expertise in C/C++, SIP, VoIP, and WebRTC technologies. The candidate will be responsible for developing, integrating, configuring, and maintaining FreeSWITCH-based telephony solutions and integrating them with Contact Center as a Service (CCaaS) platforms.

Key Responsibilities

• Develop, customize, and maintain FreeSWITCH modules and dialplans using C/C++.
• Implement FreeSWITCH Event Socket Library (ESL) and API integrations.
• Configure and troubleshoot SIP signaling, SIP trunks, RTP, SRTP, NAT traversal, and codec settings.
• Work with WebRTC technologies, including ICE, STUN/TURN, DTLS-SRTP, SDP, mod_verto, and WebSocket Secure (WSS).
• Integrate FreeSWITCH with contact center platforms and custom CCaaS solutions.
• Configure Automatic Call Distribution (ACD), skill-based routing, and queue management using mod_callcenter or FIFO queues.
• Implement call recording, call monitoring, supervisor whisper/barge, and related contact center features.
• Monitor system health, analyze logs, troubleshoot production issues, and respond to incidents.
• Manage gateway deployments, configuration changes, codec optimization, and call-quality improvements.
• Prepare technical documentation, operational runbooks, and standard operating procedures (SOPs).
• Collaborate with cross-functional teams to ensure system reliability, scalability, and performance.

Mandatory Skills

• Hands-on experience with FreeSWITCH development and configuration.
• Strong programming skills in C and C++.
• Good understanding of SIP protocols and SIP trunk configuration.
• Experience with FreeSWITCH dialplans, modules, and ESL/API integrations.
• Knowledge of RTP, SRTP, NAT, codec configuration, and media optimization.
• Hands-on understanding of WebRTC, ICE, STUN/TURN, DTLS-SRTP, SDP, and WSS.
• Experience in troubleshooting VoIP and real-time communication systems.

Good-to-Have Skills

• Experience with Asterisk or similar telephony platforms.
• Experience integrating FreeSWITCH with CCaaS or contact center solutions.
• Knowledge of ACD, skill-based routing, FIFO queues, and supervisor features.
• Experience with production monitoring, incident management, and log analysis.

Qualifications

• B.E./B.Tech in Computer Science, Electronics, Telecommunications, or an equivalent discipline.
• Minimum 5 years of relevant experience in FreeSWITCH, VoIP, SIP, or telecom software development.
• Strong analytical, debugging, problem-solving, and communication skills