Senior Technical Support Engineer (SIP / VoIP / FoIP)

ZipRecruiter; Philadelphia (Philadelphia County); Remote; USD 70,000 - 100,000; Full time

Job summary

A leading company is seeking a Technical Support Engineer to join their growing customer support team. In this senior role, you will troubleshoot SIP and VoIP issues, ensuring customer satisfaction and resolving complex technical problems. The ideal candidate will have a strong background in networking and VoIP protocols, with excellent communication skills and a passion for technology.

Benefits

Competitive salary with profit-sharing bonus

Generous PTO

Healthcare benefits

401(k) plan

Flexible work environment

Opportunities for growth

Qualifications

• Strong understanding of networking fundamentals and VoIP/SIP protocols.
• Experience with fax or FoIP is a plus.
• Proficiency with Wireshark and help desk systems.

Responsibilities

• Provide escalated support for FoIP and SIP issues via email, phone, and Zendesk.
• Diagnose SIP signaling problems, call failures, and quality issues.
• Analyze SIP traces, PCAPs, and logs with tools like Wireshark.

Skills

Troubleshooting

Customer Service

Networking Fundamentals

VoIP/SIP Protocols

Methodical Problem Solving

Communication Skills

Education

Bachelor's in Computer Science or related field

Tools

Wireshark

Zendesk

Jira

ServiceNow

Job description

Job Description

Salary:

T38Fax is seeking an experienced Technical Support Engineer with extensive experience troubleshooting SIP / VoIP / FoIP issues in a customer-facing role. We are scaling our customer support team to support the growth of our T.38 Fax Over IP (FoIP) service. This senior role requires a strong understanding of network fundamentals and a proven track record in troubleshooting SIP and VoIP calls. Experience diagnosing facsimile transmissions over SIP, especially T.38 Fax Over IP, is highly desirable.

About Fax

Fax remains vital in many business operations. According to Business Research Insights, the global fax market was valued at $2.36 billion in 2023 and is projected to reach $4.25 billion by 2032, growing at a CAGR of nearly 7%. Despite this, many VoIP and cloud-based phone providers lack support for fax over SIP, which our fax-enabled SIP trunks now address effectively.

About You

You will diagnose and resolve customer issues related to SIP trunking, T.38 fax, call quality, and network setup. You are passionate about technology, troubleshooting, and customer service, with an entrepreneurial attitude and a methodical approach to complex problems.

Your Responsibilities

1. Provide escalated support for FoIP and SIP issues via email, phone, and Zendesk.
2. Diagnose SIP signaling problems, call failures, and quality issues.
3. Analyze SIP traces, PCAPs, and logs with tools like Wireshark and tcpdump.
4. Support T.38 Fax over IP, troubleshooting failed transmissions.
5. Work with PBX systems, VoIP gateways, and SBCs.
6. Assist with network configurations, NAT traversal, and firewalls.
7. Escalate complex issues and collaborate with vendors.
8. Own customer issues and document troubleshooting steps and solutions.
9. Create documentation and knowledge base articles.
10. Test interoperability and create user guides for VoIP equipment.

Qualifications

• Bachelor's in Computer Science or related field, or equivalent experience.
• Strong understanding of networking fundamentals and VoIP/SIP protocols.
• Experience with fax or FoIP is a plus.
• Proficiency with Wireshark.
• Experience with Asterisk, Kamailio, FreeSWITCH, OpenSIPS, or cloud VoIP APIs.
• Knowledge of Linux/Unix.
• Methodical troubleshooting skills.
• Experience with help desk systems like Zendesk, Jira, or ServiceNow.
• Excellent communication skills for technical and non-technical audiences.

Our Expectations

• Focus on customer satisfaction.
• Desire to learn continuously.
• Clear and concise communication.
• Ability to multitask and prioritize.
• Follow procedures and suggest improvements.

What We Offer

• Competitive salary with profit-sharing bonus.
• Casual, flexible work environment (remote/hybrid/in-office).
• Generous PTO, healthcare, 401(k), and other benefits.
• Team-oriented culture with opportunities for growth.

Work Location & Compensation

Roles are remote, hybrid, or in-office at our headquarters in Conshohocken, PA. Compensation varies based on location and work arrangement.

Our Story

Founded in 2016, T38Fax provides fax-optimized SIP trunks to US and Canadian businesses. Recognized for rapid growth, we maintain a small, agile team committed to innovation and excellence. We offer a rewarding environment for those passionate about technology and customer service.

If you're interested, please submit your cover letter and resume, or a creative application as described.