Senior VoIP Test Engineer

Role: Senior VoIP Test Engineer

Location: Mountain View CA

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.

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.

Key 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

Required Qualifications (Must-Have)

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 Qualifications

• 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

Critical Attributes for Success

• Structured troubleshooting mindset
• Strong protocol-level knowledge
• Ability to work hands-on in lab daily
• High attention to detail
• Long-term relocation commitment and stability