Senior Unified Communications Engineer — Cisco & Microsoft Teams (M/F) - Permanent contract,

Would you like to join a dynamic, market-leading company with a broad portfolio of solutions? Telkea Group is looking for a Senior Unified Communications Engineer to design, deliver and support advanced Cisco and Microsoft Teams telephony environments for its clients.

Mission

You will join the UC Cisco & Applications team of Telkea ICT S.A. as a senior engineer, taking ownership of Cisco Unified Communications and Microsoft Teams telephony solutions throughout their full lifecycle — from architecture and design to implementation and advanced troubleshooting.

You will act as the technical reference and escalation point for complex projects and incidents, working both on our own platforms and on site at our clients in Luxembourg and the Greater Region, in a demanding professional environment that calls for rigour, autonomy, a strong sense of service and sound priority management.

Key responsibilities

As part of your role, you will notably be expected to:

• Design unified communications solutions (Cisco UC, SIP, Microsoft Teams) tailored to client requirements, producing high- and low-level designs (HLD/LLD).

• Lead the implementation and deployment of UC solutions: CUCM clusters, voice gateways, SBC/CUBE, SIP trunks, Cisco IP phones, Jabber/Webex, voicemail and Microsoft Teams calling.

• Define and build dial plans, call routing, numbering plans and class-of-service policies across multiple sites.

• Act as the L3 escalation point: diagnose and resolve complex voice, network and UC incidents.

• Own UC security: certificates and PKI, TLS/SRTP, secure registration (CTL/ITL, mixed-mode clusters) and toll-fraud prevention.

• Integrate UC with the surrounding ecosystem: AD/LDAP, presence, voicemail, monitoring and ticketing tools.

• Lead migrations and upgrades, including Cisco-to-Teams and hybrid telephony scenarios.

• Provide technical leadership and mentoring to technicians and junior engineers, and contribute to internal best practices.

• Liaise with clients, vendors and internal teams, ensuring quality, clear communication and adherence to project timelines.

• Produce and maintain clear technical documentation (designs, configurations, as-built and operating procedures).

Candidate profile

You hold a higher-education degree in IT, networks or telecommunications (Bachelor's or Master's level), or have equivalent professional experience. You have a minimum of 5 years' experience in unified communications projects, in a combined design, implementation and support role.

You have a proven ability to design a solution, implement it and troubleshoot it end to end, and you are comfortable operating autonomously in a structured, client-facing environment with high service expectations. You manage priorities well and keep professional, clear communication in all circumstances.

Cisco certifications (CCNP Collaboration / CCIE Collaboration) are strongly appreciated; Microsoft certifications (Teams / Microsoft 365 MS-700 - 721) are a plus.

Skills

• Cisco Unified Communications expertise is mandatory: deep knowledge of CUCM, Unity Connection, IM&P, Jabber, Webex, Cisco IP phones, voice gateways and SBC/CUBE.

• In-depth command of the SIP protocol (signalling, SDP negotiation, troubleshooting) and of RTP/SRTP media flows.

• Strong UC security and certificate knowledge: TLS, SRTP, PKI and certificate management, secure registration (CTL/ITL), mixed-mode clusters and toll-fraud mitigation.

• Solid IT networking foundation: TCP/IP, VLAN, DHCP, DNS, routing and end-to-end QoS for voice.

• Microsoft Teams telephony is ideal: Teams Phone, Direct Routing, SBC integration, voice routing policies and hybrid Cisco/Teams scenarios.

• Solution design and engineering: dial plan design, high availability and redundancy, Call Admission Control and capacity planning.

• Advanced troubleshooting using SIP/SDL traces, RTMT, Dialed Number Analyzer and packet captures (Wireshark).

• Project and documentation skills: ability to lead technical projects and produce clear, structured documentation.

Languages

• Native or fluent proficiency in French or English, combined with a good professional working knowledge of the other language.

• Knowledge of Luxembourgish is an advantage.

Work environment

The role is based in Luxembourg and combines project and design work with on-site interventions at our clients in Luxembourg and the Greater Region. You will work in an environment where service quality, responsiveness, precision and communication are essential.

This position will suit an experienced professional who wishes to take ownership of complex unified communications projects, deepen their expertise on Cisco and Microsoft solutions, and act as a technical reference within a leading ICT integrator.

What we offer

• A permanent, full-time contract.

• An attractive package.

• Continuous training and genuine opportunities to grow within the company.

• A dynamic, close-knit team and a very pleasant working environment.

• A company where both employees and clients are at the heart of everything we do.

• A leading group whose Luxembourg headquarters keeps organization, solutions and market expectations closely aligned.

About Telkea Group

Telkea Group, founded in 1929 in Luxembourg, currently employs more than 150 people across a wide range of activities, serving the finance sector (PSF accreditation), healthcare, hospitality, industry, services, the public sector and the European institutions.

Telkea Group (Telkea ICT, Telkea Security, Telkea Telecom and Telkea Soft) provides ICT integration, Cloud services, building security, audiovisual integration and telecom operator services in Luxembourg and the Greater Region, together with a broad range of IT solutions and a business-application publishing service.

We support public administrations, large enterprises and SMEs with the same clear vision: to be a reliable, flexible and innovative partner.

How to apply

Do you have the qualities described above? Please send your cover letter and curriculum vitae (in English or French) to jobs@telkea.com, quoting “Application for the Senior Unified Communications Engineer position (M/F)”.

Your application will be treated in the strictest confidence.