Senior Network Engineer - DoD Voice & Security

Castalia Systems; United States; On-site; USD 110,000 - 160,000; Full time

Benefits offered by this job

Medical dental and vision coverage

401k matching

generous PTO paid holidays

professional training opportunities

pet insurance

Job summary

Castalia Systems is seeking a Senior Network Engineer for a 100% onsite role in Largo, Florida. The position focuses on implementing network security and information assurance solutions, maintaining DoD‑grade networks, and supporting enterprise voice and data infrastructure.

The role requires Cisco CUCM/Unity, VOIP platforms, STIG compliance, and collaboration with cybersecurity teams to ensure secure, reliable operations in a defense context.

Qualifications

• Bachelor's degree with 12 months relevant experience or 6 years if no degree.
• DoD 8570 IAT Level II certification required/maintained.
• Security or CISSP preferred.
• Strong networking and security systems knowledge.
• Excellent written and verbal communication.
• Ability to work independently with limited oversight.
• Analytical and problem-solving skills.

Responsibilities

• Configure, administer and maintain CUCM clusters in enterprise and classified environments.
• Manage Unity Connection voicemail systems and related call flows.
• Configure dial plans, SIP trunks, and voice gateway infrastructure.
• Provide Tier III support for voice routing, signaling and QoS issues.
• Develop upgrade runbooks, patches, and maintenance schedules.

Skills

DoD 8570 IAT II

Networking fundamentals

Security best practices

VoIP troubleshooting

Independent worker

Education

Bachelor's degree

Tools

Juniper SRX/EX routers

CUCM/UCCX

Job description

Castalia Systems is seeking a Senior Network Engineer for a 100% onsite role in Largo, Florida. The position focuses on implementing network security and information assurance solutions, maintaining DoD‑grade networks, and supporting enterprise voice and data infrastructure.

The role requires Cisco CUCM/Unity, VOIP platforms, STIG compliance, and collaboration with cybersecurity teams to ensure secure, reliable operations in a defense context.