VoIP Technician - Tier III

Job Summary

We are seeking an experienced Tier III VoIP Technician to provide advanced technical support for our voice and network environments. This position serves as a senior escalation point for complex VoIP, SIP, RTP, and network-related issues that cannot be resolved through standard Tier I or Tier II troubleshooting.

The ideal candidate has a strong understanding of SIP-based voice communications, IP networking, and real-time media troubleshooting. This individual should be comfortable analyzing packet captures, diagnosing call-flow and audio issues, working directly with customers, and taking ownership of technically challenging cases through resolution.

Key Responsibilities

• Serve as a Tier III escalation point for complex VoIP, network, and customer-impacting technical issues.
• Troubleshoot SIP signaling, registration, authentication, call routing, call setup, and call teardown issues.
• Diagnose RTP and media-related problems, including one-way audio, no audio, intermittent audio, latency, jitter, and packet loss.
• Analyze SIP traces, call logs, packet captures, and other diagnostic information to determine root cause.
• Use tools such as Wireshark and related network diagnostic utilities to troubleshoot signaling and media problems.
• Troubleshoot network connectivity and voice-quality issues involving TCP/IP, UDP, DNS, DHCP, NAT, VLANs, routing, firewalls, and QoS.
• Identify problems involving customer networks, firewalls, routers, switches, SIP devices, carriers, and upstream service providers.
• Work directly with customers to gather technical information, reproduce issues, explain findings, and coordinate resolution.
• Take ownership of escalated cases from initial investigation through resolution and customer communication.
• Collaborate with internal support, engineering, operations, and network teams on complex or recurring technical issues.
• Escalate carrier or vendor-related issues when appropriate and provide the technical evidence necessary to drive resolution.
• Document troubleshooting steps, root causes, resolutions, and relevant technical findings in support tickets.
• Identify recurring problems and recommend improvements to processes, documentation, monitoring, or system configuration.
• Assist Tier I and Tier II technicians with advanced troubleshooting and technical guidance.
• Contribute to internal knowledge-base documentation and troubleshooting procedures.

Required Qualifications (MUST HAVE)

1) Advanced understanding of SIP signaling and RTP media.

2) Ability to read and interpret SIP call flows, headers, response codes, SDP, and related signaling information.

3) Experience analyzing packet captures using Wireshark or similar tools.

4) Strong understanding of IP networking concepts, including:

• TCP/IP and UDP
• DNS and DHCP
• NAT
• VLANs
• Routing and subnetting
• Firewalls and access-control rules
• QoS and traffic prioritization

5) Experience troubleshooting voice-quality issues such as latency, jitter, packet loss, one-way audio, and dropped calls.

6) Ability to distinguish between application, endpoint, network, carrier, and customer-environment issues.

7) Minimum of 3 years of experience working directly with customers on complex technical problems.

8) Strong written and verbal communication skills, including the ability to explain technical issues clearly to both technical and non-technical audiences.

9) Strong analytical and problem-solving skills with the ability to independently investigate complex issues.

10) Ability to manage multiple escalated cases while maintaining accurate technical documentation.

Preferred Qualifications

• Experience supporting hosted or cloud-based VoIP platforms.
• Experience with SIP trunks, SBCs, IP phones, ATAs, and related voice infrastructure.
• Familiarity with common PBX and unified communications platforms.
• Experience troubleshooting carrier and PSTN-related call-routing issues.
• Familiarity with Linux command-line troubleshooting.
• Experience with network monitoring, logging, or centralized diagnostic platforms.
• Networking or VoIP certifications such as CCNA, Network+, SIP School, JNCIA-Junos or equivalent practical experience.
• Previous experience in a Tier III, senior technical support, NOC, telecom, or network engineering environment.

What Success Looks Like

A successful Tier III VoIP Technician can take an ambiguous customer-reported voice problem, methodically isolate the issue, gather and interpret the necessary technical evidence, identify the root cause, and drive the issue to resolution.

This role requires someone who is comfortable going beyond scripted troubleshooting and understands how voice applications, SIP signaling, RTP media, and IP networks interact in real-world environments.

Ideal Candidate

You are naturally curious and persistent when troubleshooting difficult technical problems. You do not stop at identifying a symptom—you want to understand why the problem occurred and how to prevent it from happening again.

You are equally comfortable reviewing a SIP trace or packet capture and communicating with a customer about what is happening. You take ownership of escalations, document your findings clearly, and work effectively across teams to resolve complex issues.