Senior Technical Support Engineer; SIP​/VoIP​/FoIP

Position: Senior Technical Support Engineer (SIP / VoIP / FoIP)
T38

Fax is seeking an experienced Technical Support Engineer with a wealth of experience troubleshooting SIP / VoIP / FoIP issues in a customer-facing role. We're excited to be scaling our customer support team to keep up with the rapid growth of our popular T.38 Fax Over IP (FoIP) service. In this senior-level role we expected you to be well-versed in fundamental network concepts, with a demonstrated history of troubleshooting customer SIP and VoIP calls.

The ideal candidate will also have experience diagnosing facsimile transmissions over SIP, especially if that experience involved T.38 Fax Over IP sessions.

First, a Word About Fax

Fans of John Oliver's "How Is This Still A Thing" segments might be amused to learn that fax remains deeply entrenched in the way many companies transact their daily business. Indeed, it seems fax is still very much a thing! In its annual report on the fax industry, Business Research Insights reports that the global fax market size was 2.36 billion in 2023 and is projected to reach 4.25 billion by 2032 at a compound annual growth rate (CAGR) of almost 7%.

It's especially surprising, then, that most modern VoIP/SIP and cloud-based phone companies neither support fax over SIP nor understand how they might do so (until we show them how easy it is). Our fax-approved SIP trunks are ready to go today and fill a vital need in a growing and underserved industry that shows no signs of slowing down for many years to come.

About You

As a Technical Support Engineer you will be responsible for diagnosing and resolving customer issues related to SIP trunking, T.38 fax transmissions, call quality, and network configurations. You will work closely with customers, internal teams, and vendors to ensure seamless communication experiences. You are a proud, card-carrying tech-geek with a superhero's penchant for helping others. You breathe all things engineering, innovation, and data.

Logic is your friend, and you use it generously. Equipped with an entrepreneurial attitude, you are relentlessly energetic and excited by new challenges. If you aren't multi-tasking, it means you are under-challenged. You don't just capture packets, you use science (not superstition) to tame them.

Your Mission

This is absolutely not an IT help-desk role. We call our support team 'engineers' because of the highly technical nature of troubleshooting SIP and T.38 at industrial scale. You will:

• Provide Escalated (Tier
  3) support for FoIP and SIP-related technical issues via email, phone and case management system (Zendesk).
• Diagnose and troubleshoot SIP signaling, call setup failures, one-way audio, jitter, latency, and packet loss.
• Analyze SIP traces, PCAP captures, and logs using tools like Wireshark and tcpdump.
• Support T.38 Fax Over IP (FoIP) implementations, troubleshooting failed fax transmissions and improving reliability.
• Work with PBX systems (Asterisk, FreePBX, 3CX, etc.), VoIP gateways, and SBCs.
• Assist customers with network configurations, NAT traversal and firewall rules.
• Escalate complex issues to engineering teams and collaborate with vendors as needed.
• Take ownership of reported customer issues and see problems through to resolution, ensuring proper recording and closure of all issues.
• Write documentation, knowledge base articles and FAQs, and document troubleshooting steps, best practices and solutions in the company's knowledge base for use by both internal staff and customers.
• Test interoperability of new VoIP/FoIP equipment and create user guides for various IP-PBX and SIP-compatible devices for use with our SIP Trunking service.

Qualifications

Expert-level support is a core component of our brand and is deeply ingrained in our culture. We look for a mix of the technical expertise, troubleshooting skills, and industry knowledge that will be needed to solve complex problems, including:

• Bachelor's Degree in Computer Science or related field, or combination of education and experience may be considered.
• Solid understanding of networking fundamentals (TCP/IP, DNS, DHCP, NAT, VPNs and firewall rules) and networking protocols, in particular VoIP/SIP.
• Experience with fax and/or FoIP a plus.
• Experience with…