Senior VoIP Test Engineer
Role summary
Seeking a Senior VoIP Test Engineer to support a cloud-based telephony platform migration. This role focuses on carrier-grade SIP validation, ATA/CPE device testing, TR-069 provisioning, and large-scale endpoint migration within a lab environment. Responsibilities include designing and executing test plans, troubleshooting SIP signaling, validating secure sessions, and automating workflows using Python and REST APIs. The ideal candidate possesses deep protocol-level expertise, strong troubleshooting skills, and an automation mindset to ensure platform reliability at scale. Experience with Wireshark, SQL, and networking fundamentals is essential.
About the Company
Seeking a highly skilled Senior VoIP Test Engineer to support the migration and validation of its residential and enterprise voice platform as part of a transition from Voice to a third-party cloud-based telephony platform.
About the Role
This role is focused on carrier-grade SIP validation, ATA/CPE device testing, TR-069 provisioning, and large-scale endpoint migration testing within a hands-on lab environment. The ideal candidate brings deep protocol-level expertise, strong troubleshooting capability, and an automation mindset to ensure platform reliability at scale.
Responsibilities
- Design and execute comprehensive VoIP regression and migration validation test plans
- Validate ATA/CPE provisioning workflows using TR-069
- Perform end-to-end validation of:
- SIP registration
- Inbound/outbound calling
- Voicemail
- E911 routing
- Billing alignment
- Troubleshoot SIP signaling issues using packet-level analysis (Wireshark)
- Validate SIP over TLS and SRTP sessions including certificate negotiation and encryption issues
- Test devices behind NAT/firewalls and validate RTP/media path behavior
- Conduct interoperability testing between ATAs, SBCs, and cloud voice platforms
- Perform firmware validation and lifecycle testing of CPE devices
- Reproduce and isolate VoIP defects observed in production
- Automate repetitive validation workflows using Python and REST APIs
- Use SQL queries to validate provisioning accuracy and migration completeness
- Support production-readiness validation prior to platform cutover
Qualifications
- Carrier-Grade VoIP Expertise
- Strong hands-on experience with SIP protocol (REGISTER, INVITE, BYE, CANCEL, OPTIONS)
- Deep understanding of SIP response codes, authentication flows, and retransmission behavior
- Strong knowledge of SDP negotiation and RTP/RTCP validation
- Experience troubleshooting SIP over TLS and SRTP
- CPE / ATA Device Experience
- Hands-on experience with ATA devices (Poly, Grandstream, or similar)
- Strong experience with TR-069 remote provisioning and zero-touch configuration
- Experience validating device behavior behind NAT and residential gateways
- Test Engineering & Validation
- Experience designing and executing VoIP regression test cases
- Experience performing negative testing (malformed SIP headers, auth failures, TLS failures)
- Experience performing scale testing of endpoint registrations
- Strong Wireshark packet capture and log analysis expertise
- Automation & Validation
- Proficiency in Python scripting
- Experience automating bulk SIP registration validation
- REST API validation experience
- SQL knowledge for reconciliation and migration verification
- Networking Fundamentals
- Strong understanding of TCP/UDP, NAT traversal, firewall behavior, QoS, VLANs
- Experience troubleshooting VoIP in residential and enterprise network environments
Preferred Skills
- Experience in ISP / telecom / ITSP environments
- Experience with SBC platforms (AudioCodes, Ribbon, CUBE, etc.)
- Experience with SIP load testing tools (e.g., SIPp)
- Experience working in a VoIP lab environment
- Experience supporting high-scale residential voice deployments
