ABOUT US

UniVoxx is a VoIP telecom provider specializing in reliable, secure, and scalable communication solutions for businesses nationwide. We design, deploy, and manage advanced VoIP platforms that keep our customers connected and productive.

POSITION OVERVIEW

We are seeking a talented FreeSWITCH & Kamailio Developer to join our technical team. This role is responsible for designing, developing, and maintaining carrier-grade VoIP infrastructure using FreeSWITCH, Kamailio, and related technologies. The position also involves testing phone firmwares, troubleshooting system issues, and optimizing VoIP performance for our customers.
You will collaborate closely with our support, implementation, and development teams to ensure a high-quality, reliable VoIP experience for all users.

REQUIRED QUALIFICATIONS

• Technical Skills
• Strong hands-on experience with FreeSWITCH and Kamailio (installation, configuration, tuning).
• Deep understanding of SIP, RTP, WebRTC, and VoIP protocols.
• Proficiency in scripting languages (Lua, Python, Bash, or Perl).
• Familiarity with SQL and NoSQL databases.
• Experience with Linux server administration (Debian/Ubuntu/CentOS).
• Understanding of NAT traversal, STUN/TURN, and SBC principles.
• Tools & Troubleshooting
• Proficiency with packet analysis tools (Wireshark, sngrep, Homer/HEP).
• Experience with monitoring systems (Grafana, Prometheus, Nagios, etc.).
• Soft Skills
• Strong problem-solving abilities and attention to detail.
• Clear written and verbal communication skills.
• Ability to work independently and in a team environment.

PREFERRED QUALIFICATIONS

• Experience with HA and clustering in FreeSWITCH and/or Kamailio.
• Knowledge of carrier interconnection, SIP trunking, and LCR.
• Experience with cloud hosting environments (AWS, Azure, DigitalOcean).
• Familiarity with VoIP phone provisioning systems and firmware management.
• Exposure to other VoIP platforms (Asterisk, OpenSIPS) is a plus.
  Job Type: Full-time
  Pay: $90,000.00 - $110,000.00 per year

Benefits:

• Paid time off
• Referral program
• Relocation assistance

Work Location: In perso

• Development & Maintenance
• Design, configure, and maintain FreeSWITCH and Kamailio servers for scalability, security, and high availability.
• Create and maintain SIP routing logic, dial plans, and call handling scripts.
• Integrate FreeSWITCH/Kamailio with APIs, databases, and third-party systems.
• Troubleshooting & Optimization
• Diagnose and resolve VoIP-related issues (SIP signaling, RTP streams, NAT, call quality, etc.).
• Perform packet captures (SIP/RTP) and analyze call flow to resolve issues.
• Monitor and tune system performance to ensure uptime and call quality.
• Firmware Testing
• Test and evaluate new phone firmware releases for compatibility, features, and stability.
• Report, document, and troubleshoot firmware-related issues.
• Coordinate with phone vendors to resolve bugs and request enhancements.
• Security & Compliance
• Implement security best practices for SIP/VoIP platforms.
• Protect against SIP fraud, DoS/DDoS, and unauthorized access.
• Collaboration
• Work closely with support teams to resolve escalated VoIP issues.
• Provide documentation, training, and knowledge transfer to other team members.
• Participate in code reviews and contribute to internal tooling.