Voice Engineer

Role: Senior Voice Engineer - FreeSWITCH Specialist]

Location: Bangalore / Hyderabad/Chennai

We are looking for a Senior Voice Engineer with 5+ years of experience to design, build,

optimize, and support FreeSWITCH-based voice platforms. You will own SIP call flows end-to-end, integrate with SIP trunks/SBCs, troubleshoot complex signaling and media issues, and

ensure high availability, performance, and security of production voice infrastructure.

Responsibilities:

Design, deploy, and maintain FreeSWITCH in production (multi-node, HA and failover

setups).

Build and manage dialplans (XML/Lua), call routing rules, DID handling, and multi-tenant

call flows.

Configure SIP profiles (internal/external), gateways, trunks, registrations, NAT traversal

and interoperability.

Troubleshoot SIP signaling and RTP/media issues (one-way audio, no-audio, codec

mismatch, re-INVITE, session timers).

Implement and tune codec strategies (G.711, Opus, etc.), transcoding, jitter buffer

settings, and media bypass where applicable.

Ensure reliable DTMF handling (RFC2833/telephone-event, in-band, SIP INFO) end-toend.

Implement voice security best practices including TLS/SRTP, certificate management, IP

allowlists, rate limits and fraud controls.

Set up monitoring and alerting for voice KPIs (CPS, concurrent calls, registration health,

packet loss/jitter/RTCP).

Perform incident response (L2/L3), root-cause analysis, and preventive improvements;

participate in on-call rotations as needed.

Integrate with SBCs/proxies (e.g., Kamailio/OpenSIPS), PSTN gateways, and WebRTC

stacks (ICE/STUN/TURN/SDP) when required.

Automate provisioning and deployments using scripting and CI/CD; maintain clear

operational runbooks and documentation.

Collaborate with product, development, network, and operations teams; mentor junior

engineers.

Experience

5+ years of experience in VoIP/voice engineering with strong hands-on FreeSWITCH

expertise.

Strong understanding of SIP, SDP, RTP/RTCP, NAT traversal, and end-to-end call flows.

Hands-on experience with FreeSWITCH dialplans and scripting (Lua preferred; Python

acceptable).

Strong troubleshooting using tools like sngrep, tcpdump, Wireshark, and FreeSWITCH

logs (fs_cli).

Production support experience, including performance tuning for CPS/concurrent calls

and high-availability operations.