QA Engineering Specialist

Role: VoIP / SIP Automation Tester
Type: Contract (6 Months)

Location: Ipswich, UK

Working Model: Hybrid (3 days per week in office)

About the Role

We are looking for a Senior QA Automation Engineer who enjoys digging deep into real-time voice protocols while building clean, resilient automated test suites. In this role, you'll help ensure our core VoIP and video infrastructure remains rock-solid, reliable, and secure under high load.

You won't just be running scripts-you'll design automated test frameworks, trace complex call flows down to the packet level, and help shape deployment decisions alongside our dev and network teams.

What You'll Do

• Build & Scale Automation: Design and maintain test automation frameworks for signaling, media processing, and regression testing using Python and Robot Framework.
• Simulate Real-World Load: Script high-volume stress tests, concurrent call simulations, and network degradation scenarios to test infrastructure limits.
• Integrate with CI/CD: Embed test suites directly into deployment pipelines (Jenkins, GitLab, GitHub Actions) for continuous feedback.
• Analyze & Diagnose Traffic: Use Wireshark and tcpdump to dissect PCAPs, trace call flows, and troubleshoot one-way audio, dropped calls, or media issues.
• Validate Telecom Protocols: Test and verify SIP signaling, SDP negotiations, and encrypted/unencrypted media flows (RTP/SRTP).
• Track System Quality: Monitor critical metrics like latency, jitter, packet loss, and MOS scores to safeguard voice quality.
• Document & Collaborate: Author detailed test scenarios in Jira, log issues with clean SIP ladder diagrams and logs, and partner closely with DevOps and Network Engineers to resolve root causes.

What We're Looking For

Essential Experience

• Hands-on performance & call testing experience using tools like SIPp, Spectra, WinSIP, or StarTrinity.
• Strong automation skills in Python and Robot Framework .
• API and performance testing experience with tools like Locust, k6, JMeter, BlazeMeter/Taurus, or Newman.
• UI automation experience with TestCafe.
• Direct experience integrating test automation into CI/CD pipelines.
• Solid working knowledge of Linux (RHEL, CentOS, OEL) and Windows Server environments, including core services like DNS, DHCP, LDAP, and Active Directory.
• Familiarity with telecom media engines and SBCs (such as Metaswitch Rhino, Dialogic Media Server, or Perimeta SBC).
• Understanding of security hardening and ITIL practices for telecom applications.

If Interested please share your CV to rhea. bhattacharya1 @randstad (url removed)

Randstad Technologies is acting as an Employment Business in relation to this vacancy. </p

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