System Engineer (VoIP & Network Access)

ABOUT THE TEAM

• Technology Delivery International (TDI) is a key part of Deutsche Telekom, driving innovation across Europe. We deliver the full product lifecycle of telecommunications IT and network technology solutions - from engineering and architecture to development, testing, providing infrastructure, and managing operations. Our international teams work closely with Deutsche Telekom’s national companies to bring these solutions to life, ensuring seamless delivery and continuous improvement. Team Members are also working from Hungary within the local organization that we have at Magyar Telekom.
• We are looking for a motivated, dynamic, and positive System Engineer (VoIP Expert) to join our B2B team. This role focuses on testing, validation, integration, and optimization of CloudPBX telephony and collaboration solutions in a multi-vendor Unified Communications (UC) environment.
• The ideal candidate has a strong background in VoIP, SIP, UC clients, CPEs, cloud-based communication systems and broadband access technologies, with the ability to troubleshoot, test, and enhance end-to-end telephony solutions.You will collaborate closely with internal engineering teams, product management, vendors, and international colleagues, especially the German teams, to ensure service stability, interoperability, and innovation across all platforms.
• Long-term outlook: You will be increasingly involved in automation activities, including writing test cases and test steps for different terminal development projects. Therefore, experience or strong interest in test automation and scripting (Python/Java) is highly desirable.

WHAT YOU'LL BE DOING

• Test, validate, and troubleshoot CloudPBX, SIP/VoIP services, IMS components, UC clients, and CPE devices.
• Conduct CPE, interoperability, regression, and security testing (including SIP/TLS).
• Analyze SIP/RTP flows, codecs, QoS, and network behaviors using Wireshark, SIPp, and similar tools.
• Develop and automate test cases using Python or Java.
• Collaborate with vendors, product managers, and international teams to analyze defects, plan releases, and ensure feature readiness.
• Work with GitLab, CI/CD pipelines, and support cloud environments (AWS, Azure) related to CloudPBX and UC services.
• Document test results and provide recommendations for product improvement and deployment support.

WHAT WE’RE LOOKING FOR

• University degree (preferred in Computer Science, Telecommunication Engineering, Information Systems, or comparable qualification)
• Fluent in English (German is highly appreciated.)
• 2+ years proven experience in technologies.
• Networking & Protocols
• Strong knowledge of TCP/IP, IPv4/IPv6, OSI model, PPPoE, DHCP, VRRP, L2 VPN, Ethernet, VDSL/SHDSL.
• Experience with SNMP, RADIUS, DNS, SSH.
• Understanding of Wi-Fi, VPN, Fixed Wireless Network technologies, and related performance testing.
• Familiarity with SBC routing, NAT/firewall traversal, and QoS optimization.
• VoIP&UC Platforms
• Expertise in VoIP, SIP, RTP, SDP, and codec negotiation (G.711, G.722, Opus).
• Hands-on experience with IMS platforms and CloudPBX/VoIP infrastructures.
• Deep understanding of CloudPBX systems, IP-PBX, CPE routers, Asterisk PBX, and UC platforms (Microsoft Teams, Zoom, RingCentral).
• CPE testing experience (IP phones, UC clients, gateways, routers).
• Knowledge of mobile OS platforms (e.g., Android, iOS) for UC client testing.
• Familiarity with HPQC, Jira, or similar QA and defect tracking tools.
• Good understanding of TLS, cipher suites, and secure SIP communication.
• Automation & Tools
• Automation scripting skills (Python or Java) for testing and validation.
• Familiarity with GitLab, CI/CD pipelines, and Linux environments.
• Experience with cloud infrastructure and virtualization (AWS, Azure, Docker, Kubernetes).
• Understanding of network and UC security best practices.
• Exposure to Deutsche Telekom & European compliance and regulatory standards (ETSI, CE).
• Experience in test automation frameworks
• Knowledge of TR-069 / CWMP for remote device management.
• Social skills
• A mindset of continuous learning, willingness to share knowledge and learn from others.
• Ability to think outside of the box and find solutions to complex problems.
• Being a strong individual contributor and an empathic team player.
• Ability to communicate effectively with different stakeholders in the company.

WHAT YOU CAN EXPECT

• Our team is dedicated to supporting new team members and we're building an environment that appreciates knowledge sharing and mentorship. Our experienced team members are passionate about coaching junior and new members of the team.
• We take a long-term commitment when it comes to our employees. You will develop your career working in truly innovative projects of Deutsche Telekom Group, exploring the latest trends and technologies which enable the product development process.
• We offer an open and friendly working environment, competitive remuneration package and attractive benefit scheme.
• Enjoy the benefits of flexible hours, part-time roles, and remote work options - so you can balance your career with family life and personal priorities.

BENEFITS AND TRAINING OPPORTUNITIES

• Flexible working hours with partial home office options.
• Comprehensive benefits package (laptop, mobile phone, cafeteria, insurance).
• Employee discount rates on Telekom services.
• Modern, multinational working environment with amenities like a sky bar and rooftop gym.
• Access to our Employee Assistance Program.
• Comprehensive Healthcare Package
• You will receive a minimum of 25 days of basic vacation per year (based on age)
• We offer 15 days of additional vacation if you become a father, with 100% pay
• You'll have access to thousands of professional and skills development materials from our extensive digital training palette
• We offer regular internal training sessions and workshops
• You can learn English and German, even with a native speaker
• You’ll have access to Percipio and Coursera courses