The organization is seeking a Senior Cisco Unified Communications Engineer to design, administer, and sustain enterprise and classified voice and collaboration environments, with primary responsibility for Cisco CUCM, Unity Connection, VoIP infrastructure, voice gateways, SIP, conferencing, and associated collaboration platforms. The role will provide Tier III technical leadership across system engineering, troubleshooting, upgrades, modernization, and lifecycle management while ensuring DISA STIG compliance, cybersecurity hardening, configuration management, and accreditation requirements are met.