ManTech seeks a motivated, career and customer-oriented Unified Communications (UC) Operational Network Engineer to support our current GSMO-II contract supporting the Defense Information Systems Agency (DISA) critical global missions from Stuttgart, Germany. This UC/Voice Operational Engineer role provides sustainment, maintenance, problem and change management services to help ensure, reliable, and uninterrupted availability of the Department of Defense Information Network (DODIN) UC enterprise and service provider networks. This is a funded position on a multiyear contract through July, 2030. Relocation will be provided and you will have access to all base privileges to include the military commissary and BX/PX. You will also receive HOLA/COLA allowances and will have access to DoDDS Schools or international schools for all dependents. **Responsibilities include but are not limited to:** + Development of technical solutions that require collaboration with internal experts, deep analysis and understanding of impact on end-product/solutions. + Implementation and troubleshooting of routing protocols (BGP, OSPF), telephony protocols (SIP, TLS, MGCP), and interoperability between various telephony systems and service provider networks. + Configuration and troubleshooting of telephone devices and protocols including SIP, BGP, MGCP, H.323 and implementation of access control lists in different environments. + Telephony Enterprise Call Routing and Conferencing + Identification and documentation of network errors and solutions. Analysis of network and telecommunications alarms to identify potential issues. + Configuration, testing, installation, troubleshooting, and maintaining network devices and servers such as firewalls, cryptographic devices, routers, switches, SBCs, CUCMs, F5s, to optimize performance and ensure the desired security posture is attained and maintained. + Configuration, testing, installation, troubleshooting, and maintaining VoIP network devices such as CUBES, SBCs, CUCMs, firewalls, cryptographic devices, and routers to optimize performance and ensure the desired security posture is attained and maintained. + Providing high level technical support for the design, implementation and integration of network changes and sustainment in support of enterprise service provider voice networks. **Minimum Qualifications:** + Bachelor's degree in a relevant technical discipline and 4 plus years of overall related experience. (11+ years of additional related years of experience is accepted in lieu of a degree.) + Must hold DoD-8570 IAT Level 2 or higher baseline certification (Security+ CE or CCNA Security, CISSP or equivalent) + CCNA required (CNP or CCIE desired) + Experience analyzing telephony call routing, setup, design, and architecture. + Experience troubleshooting and configuring telephony VoIP networks + Experience with enterprise VoIP networks using multiple platforms (Cisco, Avaya, Oracle, Ribbon, or Raytheon) + Ability to obtain Technical Expert Status Accreditation (TESA) in Germany. **Preferred Qualifications:** + Comprehensive knowledge of the principles, methods, and techniques used in VoIP network analysis and design. + Extensive knowledge with all tasks associated with enterprise Cisco Call Manager management and high availability. + Comprehensive experience with registering and troubleshoot endpoints, VTC devices, and Jabber clients. + Comprehensive knowledge and experience with configuration and troubleshooting of voice trunks and call routing. + Comprehensive knowledge and experience with managing and troubleshooting dial plans, route patterns, and translations. + Knowledge and experience with Cisco Unity, Meeting Server, and SBCs + Comprehensive knowledge and experience with Cisco Presence (Jabber). + Certifications with major network system vendors such as Cisco + Extensive network integration experience for a variety of network protocol standards. + Excellent project, technical, interpersonal, presentation and problem management skills. + Ability to communicate orally, and in writing, detailed technical information on troubleshooting and implementation efforts. **Clearance Requirement:** + Must have an Active Secret with the ability to obtain and maintain a Top Secret **Physical Requirement** : + Sedentary work ManTech International Corporation, as well as its subsidiaries proactively fulfills its role as an equal opportunity employer. We do not discriminate against any employee or applicant for employment. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, or status as a protected veteran. If you are a qualified individual with a disability and require a reasonable accommodation to apply for a position with ManTech through its online applicant system, please email us at careers@mantech.com and provide your name and contact information.