QA Engineering Specialist

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

Location: Ipswich, UK

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

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.

• 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.

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 digital.com

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