Senior Network Engineer (VOIP)

Company: CACI
Location: Herndon
Posted on: April 2, 2026

Job Description:

Job Title: Senior Network Engineer (VOIP) Job Category: Information Technology Time Type: Full time Minimum Clearance Required to Start: TS/SCI with Polygraph Employee Type: Regular Percentage of Travel Required: Up to 10% Type of Travel: Continental US * * * The Opportunity CACI is looking for a VOIP Engineer to work as part of a collaborative, multidiscipline team in support of U.S. Government and provide technical expertise in the field of network engineering and VOIP. Responsibilities • Design, implement, and maintain Local and Wide Area Networks (LAN/WAN). • Ensure robust and scalable network infrastructure aligned with client requirements. • Demonstrate advanced knowledge of TCP/IP protocols to ensure optimal network performance. • Troubleshoot and resolve complex network issues related to TCP/IP. • Engineer and implement voice and video solutions using platforms such as Cisco, Asterisk, and 3CX. • Configure and maintain VoIP protocols including SIP, RTP, and H.323. • Configure and troubleshoot LAN switches, routers, firewalls, and VPN concentrators. • Utilize tools like Wireshark for advanced troubleshooting of complex call routing issues. • Implement and maintain security measures such as Session Border Controllers (SBCs) and Transport Layer Security (TLS). • Integrate voice systems with cloud services to enhance functionality and reliability. • Convey technical designs, ideas, and results to non-technical audiences effectively. • Provide briefings and presentations to high-level government personnel. • Author comprehensive documents including reports, briefings, and technical documentation to support customer missions. • Maintain accurate and detailed records of network configurations and troubleshooting steps. • Apply the engineering design process to discover innovative methods to solve technical problems. • Demonstrate a proven ability to meet and exceed client requirements through creative solutions. • Work collaboratively with cross-functional teams to ensure seamless integration of network and voice solutions. • Provide ongoing support and maintenance for implemented systems, ensuring they meet performance standards. Qualifications Required: • Strong background in Microsoft Systems Engineering and providing support to those systems. • Strong knowledge of virtualization products with a focus on Hyper-V. • Proficiency in scripting languages with a focus on PowerShell. • Experience with McAfee product suite. • Demonstrated capacity to understand and communicate technical ideas, concepts, and thoughts across multiple technical and non-technical stakeholders. • Demonstrated ability to independently determine and develop approach to solutions. • Must have knowledge of Cisco Routing and Switching, and network architecture planning. • Must have knowledge of remote administration and secure Virtual Private Networking. • Must understand commercial encryption standards and their application in IP networking. • Must have knowledge of VPN technologies, OSPF, EIGRP, BGP, IP Multicasting Must have knowledge of voice and video solutions to include Cisco, Polycom, and Avaya configuration management and endpoint management including SIP and H.323 protocols. • 7-10 years of relevant experience designing communications systems. • Must have strong written and oral communication skills. • Excellent analysis and critical thinking skills • Ability to work independently as well as within small and large groups • Capable of preparing and presenting briefings • Experience with Microsoft Office product line, including Microsoft Access; experience with Lotus Notes • 8with a Bachelors degree in Computer Science or related field (Equivalent experience may be substituted for educational requirement) • TS/SCI with Poly required Desired: • Knowledge of Cisco and PolyCom VTC technology • An understanding of Private Branch Exchange telephony • • An ability to navigate and configure Linux operating systems • An understanding of wired data transport mediums to include Category 5e/6 and fiber optics. • Prior deployment to foreign field areas in support of customer mission • Prior experience communicating official traffic in the customer Electronic Messaging System (EMS) • Certifications such as CCNP, CCNA, CCIE, MCSE • Familiar with military communications • Familiar with satellite and wireless communications. This position is contingent on funding and may not be filled immediately. However, this position is representative of positions within CACI that are consistently available. Individuals who apply may also be considered for other positions at CACI. What You Can Expect: A culture of integrity. At CACI, we place character and innovation at the center of everything we do. As a valued team member, you’ll be part of a high-performing group dedicated to our customer’s missions and driven by a higher purpose – to ensure the safety of our nation. An environment of trust. CACI values the unique contributions that every employee brings to our company and our customers - every day. You’ll have the autonomy to take the time you need through a unique flexible time off benefit and have access to robust learning resources to make your ambitions a reality. A focus on continuous growth. Together, we will advance our nation's most critical missions, build on our lengthy track record of business success, and find opportunities to break new ground — in your career and in our legacy. Pay Range : There are a host of factors that can influence final salary including, but not limited to, geographic location, Federal Government contract labor categories and contract wage rates, relevant prior work experience, specific skills and competencies, education, and certifications. Our employees value the flexibility at CACI that allows them to balance quality work and their personal lives. We offer competitive compensation, benefits and learning and development opportunities. Our broad and competitive mix of benefits options is designed to support and protect employees and their families. At CACI, you will receive comprehensive benefits such as; healthcare, wellness, financial, retirement, family support, continuing education, and time off benefits. The proposed salary range for this position is: $103,800 - $218,100 CACI is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, pregnancy, sexual orientation, age, national origin, disability, status as a protected veteran, or any other protected characteristic.

Keywords: CACI, Annandale , Senior Network Engineer (VOIP), IT / Software / Systems , Herndon, Virginia