Telephony Engineer

Roles & Responsibilities:

We are looking for a FreeSWITCH Implementation Engineer who will be responsible for designing, deploying, configuring, integrating, and maintaining FreeSWITCH-based VoIP platforms. The role involves working closely with SIP, RTP, WebRTC, IVR, conferencing, call routing, and external integrations in a production environment.

Key Responsibilities:

FreeSWITCH Core Responsibilities:

- Install, configure, and maintain FreeSWITCH in production environments from the scratch.

- Design and implement call flows, dialplans, IVRs, conferencing, and call routing with complete ownership.

- Configure SIP profiles (internal/external), gateways, trunks, and extensions.

- Implement multi-tenant and high-availability FreeSWITCH architectures.

SIP, RTP & Networking:

- Strong understanding of SIP signaling, RTP media, and SDP negotiation.

- Troubleshoot one-way audio, no-audio, call drops, registration failures.

- Configure NAT traversal, firewall rules, and RTP port ranges.

- Analyze SIP logs and traces (siptrace, sngrep, tcpdump).

Dialplan & Scripting:

- Develop dialplans using XML and Lua / JavaScript / Python.

- Implement logic for call queues, time-based routing, skill-based routing, and failover/fallback handling.

Integrations & APIs:

- Integrate FreeSWITCH with CRM/ERP systems, billing platforms, AI voice bots (ASR/TTS), and external WebSocket or REST services.

- Use Event Socket Library (ESL) for inbound/outbound real-time call control and monitoring.

WebRTC & Media:

- Configure WebRTC support (DTLS-SRTP, ICE, OPUS), mod_verto, and SIP over WSS.

- Implement browser-based calling solutions.

Monitoring & Debugging:

- Monitor system performance, call quality, logs, and CDRs.

- Optimize codec usage and RTP performance.

- Handle live production incidents and RCA.

Deployment & Operations:

- Deploy FreeSWITCH on Linux (CentOS / Ubuntu) and cloud platforms (AWS / GCP / Azure).

- Configure HA, load balancing, and scaling.

- Work with DevOps teams for CI/CD, backups, and automation.

Ideal Candidate:

- 4+ years of experience, with at least 3+ years of hands-on experience implementing, configuring, and supporting FreeSWITCH in production.

- Strong hands-on knowledge of VoIP technologies (SIP, RTP, RTCP, SDP, WebRTC).

- Proficiency in Linux administration, SQL (MySQL/PostgreSQL), and debugging tools (fs_cli, sngrep, tcpdump).

- Immediate joiners or those available within 15 days are highly preferred.

Skills

FreeSWITCH, VoIP, SIP, RTP, WebRTC, Linux, IP Telephony