Senior VoIP Engineer - Level III

A1FED; San Antonio (TX); On-site; USD 110,000 - 140,000; Full time

Job summary

A1FED is seeking a Senior VoIP Engineer to design, deploy, and maintain enterprise-class VoIP and UC systems across multiple sites. You will ensure voice services meet DoD STIGs and maintain high availability for critical communications in a large medical facility environment.

The role requires hands-on experience with CUCM/UCCX, gateways, SBCs, and SIP Trunk integration, plus the ability to lead migrations from legacy TDM/PBX to modern VoIP architectures. On-site in San Antonio, TX.

Qualifications

• Six (6) years of progressive experience demonstrating the required proficiency.
• Bachelor's degree and/or equivalent.
• Certifications in IAT II (at least one): CCNA – Security, SSCP, CySA+, Security+ CE, GICSP, GSEC.
• Preferred Certifications: CCNP Collaboration, CCIE Collaboration, CCNA Voice, CCVP.

Responsibilities

• System Engineering & Design: Architect enterprise VoIP and UC solutions (CUCM, UCCX, voice gateways).
• Implementation & Migration: Lead site surveys, capacity planning, deployment of VoIP hardware/software.
• Operations & Maintenance: Patch, upgrade, configure CUBE, SIP Trunks, SBCs, SRST, and QoS settings.
• Troubleshoot & Support: Escalate complex issues; analyze SIP signaling and packet captures.
• Security & Compliance: Apply DoD STIGs; support RMF accreditation with diagrams/artifacts.
• Documentation & Mentorship: Maintain topology diagrams and SOPs; mentor staff.

Skills

UC/VoIP design

VoIP troubleshooting

SIP Trunking

DoD STIGs knowledge

Packet captures analysis

Education

Bachelor's degree or equivalent

Tools

CUCM/UCCX

VoIP gateways

SBCs

SRST

QoS & VLANs

Job description

Citizenship Requirements

US Citizenship or Permanent Resident (Green Card Holder)

Location

San Antonio, TX (On-site)

Federal Background Investigation Required

Tier 3 (T3)

IT Security Designation

ADP/IT II

Relevant Experience

Six (6) years of progressive experience demonstrating the required proficiency.

Minimum Education

Bachelor's degree and/or equivalent.

IA Technical/Management Designation

• Certifications Required (at least one of the following IAT II certifications is required):
  • CCNA – Security
  • SSCP
  • CySA+
  • Security+ CE
  • GICSP
  • GSEC
• Preferred Certifications (at least one of the following):
  • CCNP Collaboration
  • CCIE Collaboration
  • CCNA Voice
  • CCVP

Role Summary

The Senior VoIP Engineer provides Tier III/IV level support for the Unified Communications (UC) and VoIP infrastructure. This role is responsible for the design, deployment, configuration, maintenance, and troubleshooting of enterprise-class VoIP systems providing telephony, automated call trees, overhead paging, 911 services, and SIP Trunk integration with other critical systems across multiple buildings composing a large Medical Treatment Facility (MTF). The engineer ensures all voice communications systems adhere to Department of Defense (DoD) Security Technical Implementation Guides (STIGS) and maintain high availability to support critical communication requirements in a Level 1 trauma center serving the city of San Antonio, and Military patients and families.

Specific Duties

System Engineering & Design

Architect and engineer enterprise VoIP and Unified Communications solutions (e.g., Cisco Unified Communication Manager (CUCM), Cisco Unified Contact Center Express (UCCX), voice gateways, analog gateways for the MTF phone system. Design complex dial plans, partitions, Calling Search Spaces (CSS), translation patterns, and route patterns.

Implementation and Migration

Lead site surveys, capacity planning, end user requirement analysis, and the physical/logical deployment of VoIP hardware and software. Migrate legacy TDM/PBX systems to modern VoIP architecture.

Operations and Maintenance

Perform routine patching, upgrades, and configuration modifications on Cisco Unified Border Element (CUBE), SIP Trunks, H.323/MGCP Gateways, session border controllers (SBCssss), Survivable Remote Site Telephony (SRST), and network configurations (QoS, trunking, Vlans, interfaces, 802.1X) to ensure continuous service availability. Configure, and optimize complex dial plans, partitions, Calling Search Spaces (CSS), translation patterns, and route patterns. Manage DID ranges, E.164 global dial plans, and emergency routing protocols. Maintain device pools, region parameters, and codec preferences.

Troubleshoot and Support

Serve as a primary escalation point for complex voice network issues. Analyze packet captures and SIP signaling to resolve jitter, latency, and call routing failures. Analyze performance on the network for non-VoIP related traffic as required.

Security & Compliance

Plan and execute major system upgrades, patches, firmware updates, and database replication health checks across the publisher and subscriber nodes. Implement DoD STIGSs for all voice network appliances and network equipment. Support Risk Management Framework (RMF) accreditation efforts by providing necessary diagrams and artifacts.

Documentation & Mentorship

Maintain accurate network topology diagrams, standard operating procedures (SOPs), and dial plan documentation. Make available to other VoIP support staff and mentor less experienced staff to build a strong team.