Senior VoIP Infrastructure Engineer (Kamailio / FreeSWITCH / SIP)

We are looking for an “Advanced VoIP Engineer” / “Senior VoIP Infrastructure Engineer” with strong experience in open SIP environments, Kamailio, FreeSWITCH, and Linux based voice infrastructure.

Core requirements

• Advanced knowledge of SIP protocol and SIP call flows
• Strong hands on experience with Kamailio
• Strong understanding of OpenSIPS or similar open SIP platforms
• Experience with FreeSWITCH, including configuration, troubleshooting, and module development
• Ability to create or modify FreeSWITCH modules
• Strong C programming knowledge
• Experience compiling applications and modules in a Unix or Linux environment
• Strong Linux background, including Debian, Ubuntu, or similar distributions
• Understanding of Linux firewalling, iptables, routing, and packet filtering
• Experience with SIP monitoring tools such as HOMER, VoIPMonitor, or SIPMon
• Strong understanding of STIR/SHAKEN
• Ability to troubleshoot SIP signaling, RTP, DTMF, NAT traversal, registration, routing, and carrier interconnect issues
• Experience working with SBCs, SIP trunks, and carrier grade VoIP environments

Ideal Candidate Profile

This person should be a true advanced VoIP engineer, not just a general telecom technician. They should understand SIP at the protocol level, be comfortable working in Linux, and have hands on experience with Kamailio, FreeSWITCH, OpenSIPS, and SIP monitoring tools. They should also be capable of debugging complex SIP issues, compiling code, and supporting custom voice infrastructure.

About the Company

We are hiring directly for one of our Client client in USA, has multiple projects/companies mostly in telecommunication industry, exact details will be shared in very first call made to the shortlisted candidates by the client

What to Expect in the Recruitment Process

• Initial Introductory Interview with Shortlisted Candidates In this quick call we will go over the Candidates Resume, Discuss in Details about the Job Description and provide insights into next steps, You will be sent a link to schedule this call as per your Convenience
• Initial Technical & Experience Discussion ( 1st Interview Round with Client ) An introductory discussion focused on the candidate’s professional experience, technical background, projects, and core areas of expertise.
• Advanced Technical Interview ( 2nd Interview Round with Client ) A deep technical interview covering real-world troubleshooting scenarios, infrastructure design, system administration, networking, security, and technologies relevant to the role.
• Final Team & Communication Interview (3rd Interview Round with Client) A final discussion focused on communication, ownership, collaboration, work ethic, project coordination, and overall alignment with the team and work environment. Candidates should expect a technically rigorous interview process with an emphasis on practical experience and real-world problem-solving

Pay: Rs250,000.00 - Rs1,000,000.00 per month

Application Question(s):

• (Yes/No) Do you have understanding of SIP at the protocol level
• (Yes/No) Are you comfortable with working in Linux, and have hands on experience with Kamailio, FreeSWITCH, OpenSIPS, and SIP monitoring tools
• (Yes/No) Are you capable of debugging complex SIP issues, compiling code, and supporting custom voice infrastructure.

Experience:

• Linux: 1 year (Preferred)

Work Location: Remote