CBTS serves enterprise and midmarket clients in all industries across the United States and Canada. CBTS combines deep technical expertise with a full suite of flexible technology solutions--including Application Modernization, Managed Hybrid Cloud, Cybersecurity, Unified Communications, and Infrastructure solutions. From developing and deploying modern applications and the secure, scalable platforms on which they run, to managing, monitoring, and optimizing their operations, CBTS delivers comprehensive technology solutions for its clients' transformative business initiatives. For more information, please visit www.cbts.com.

OnX is a leading technology solution provider that serves businesses, healthcare organizations, and government agencies across Canada. OnX combines deep technical expertise with a full suite of flexible technology solutions—including Generative AI, Application Modernization, Managed Hybrid Cloud, Cybersecurity, Unified Communications, and Infrastructure solutions. From developing and deploying modern applications and the secure, scalable platforms on which they run, to managing, monitoring, and optimizing their operations, OnX delivers comprehensive technology solutions for its clients’ transformative business initiatives. For more information, please visit www.onx.com.

Job Purpose:

VoIP Engineer – L3 provides advanced engineering and operational support for enterprise Voice over IP (VoIP) services delivered to managed services clients. This role serves as the highest level of technical escalation for VoIP-related incidents and service requests.

The position is responsible for maintaining SIP Trunking, Hosted Unified Communications (HUC), Cloud Calling, and VoIP services operating across SD-WAN environments. The engineer ensures platform stability, high availability, optimal performance, and customer satisfaction while collaborating closely with internal teams, vendors, and carriers to resolve complex issues and drive continuous service improvement.

Essential Functions

·       Serve as Tier 3 escalation point for complex VoIP, SIP, Cloud Calling, and SD-WAN voice-related incidents

·       Independently troubleshoot advanced SIP signaling, RTP/media flow, call routing, and QoS issues

·       Support enterprise VoIP services delivered over SD-WAN and hybrid network architectures

·       Diagnose and resolve voice quality issues including latency, jitter, packet loss, and WAN transport instability

·       Provide advanced support for Cloud Calling platforms (hosted voice, WxC, Teams-integrated calling environments)

·       Support new customer turn-ups, migrations, and complex VoIP/Cloud Calling change implementations

·       Participate in major incident management, Root Cause Analysis (RCA), and corrective action planning

·       Review and validate SBC, SIP trunk, and call routing configurations

·       Develop and maintain technical documentation, runbooks, SOPs, and knowledge articles

·       Mentor and provide technical guidance to junior VoIP engineers

·       Communicate effectively with customers, architects, vendors, and project/program managers

Certifications

• CCNA (or equivalent) – Required
• CCNP (Collaboration, Voice, or Enterprise) – Preferred
• VoIP, Cloud Calling, or SD-WAN vendor certifications – Preferred

Relevant Experience

• 6–9 years of experience in VoIP, Unified Communications, or Service Provider environments
• Minimum 3 years in Tier 3, advanced support, or VoIP engineering role
• Experience supporting enterprise voice services delivered over SD-WAN and cloud-based platforms ( WxC / MSTV)

Special Knowledge, Skills & Abilities

• Expert-level knowledge of SIP, RTP, SDP, codecs, and VoIP call flows
• Advanced troubleshooting experience with VoIP over SD-WAN, MPLS, and Internet-based WAN environments
• Working knowledge of Cloud Calling / UCaaS platforms and hosted voice solutions
• Strong understanding of QoS design, traffic prioritization, and WAN voice optimization
• Experience with Session Border Controllers (SBCs) and carrier interconnects
• Proficiency in analyzing call traces, packet captures, and signaling logs
• Strong written and verbal communication skills
• Ability to perform independently in high-pressure, customer-impacting scenarios
• Demonstrated ability to document processes and contribute to operational best practices