Senior Network Engineer — VOIP & Security Specialist

Dexian; Reston (VA); On-site; USD 90,000 - 140,000; Full time

Job summary

Dexian is seeking a highly experienced Network Administrator to join its IT team in Reston, VA. The role focuses on managing VOIP systems, Cisco IP Phones with ISE, and maintaining the organization’s network infrastructure for reliability and security.

Ideal candidates bring 7–10 years in network administration, strong TCP/IP, DNS, DHCP, BGP, OSPF knowledge, and hands-on Cisco/Juniper hardware experience. CCNP/CISSP preferred.

Qualifications

• Bachelor's degree or equivalent professional experience.
• 7–10 years of network administration experience, with ≥2 years VOIP management.
• Strong knowledge of TCP/IP, DNS, DHCP, BGP, and OSPF.
• Hands-on with Cisco/Juniper network hardware and security tools.
• CCNP/Network+ or CISSP highly preferred.

Responsibilities

• Design, deploy, and manage LAN/WAN, VPN, and wireless networks.
• Configure and monitor VOIP systems, Cisco IP Phones with ISE integration.
• Ensure network security with firewalls, IDS/IPS, and encryption.
• Monitor performance, troubleshoot outages, and minimize downtime.
• Document configurations, changes, and disaster recovery plans.
• Mentor junior staff and collaborate with system admins, devs, and security.

Skills

VOIP management

Network troubleshooting

Proactive network management

Cross-functional collaboration

Education

Bachelor's degree in CS/IT or equivalent

Tools

Cisco hardware

Juniper hardware

VPN technologies

Firewall/IDS/IPS

Job description

Dexian is seeking a highly experienced Network Administrator to join its IT team in Reston, VA. The role focuses on managing VOIP systems, Cisco IP Phones with ISE, and maintaining the organization’s network infrastructure for reliability and security.

Ideal candidates bring 7–10 years in network administration, strong TCP/IP, DNS, DHCP, BGP, OSPF knowledge, and hands-on Cisco/Juniper hardware experience. CCNP/CISSP preferred.