Senior Telephony Engineer (VoIP/ SIP)

ABOUT NSC SOFTWARE

NSC Software delivers premier software development and consulting services for global businesses, powered by Vietnam’s top engineering talent. With a team of 150+ IT professionals, we continuously expand our capabilities, refine our delivery processes, and adopt cutting-edge technologies to meet diverse client needs.

Guided by our core value —Premier, Talented, Innovative, Committed, Trusted and Transparent—we focus on building long-term partnerships and delivering future-ready solutions. Through this, we aim to advance Vietnam’s IT industry and create meaningful global impact.

Why should you join us?

• Remote work, flexible working environment

• Attractive salary package 

• Technical training and certifications 

• Global career opportunities
• Enhance autonomy and independence

JOB DESCRIPTION

Responsibilities

As a Senior Telephony Engineer at NSC, you will work remotely with fixed working hours from 10:00 AM – 6:00 PM (Vietnam time).

We are seeking a Telephony Engineer to who will own the technical success of our telephony integrations, act as the first line of defense for advanced enterprise telephony support, and drive seamless post-onboarding experiences. Your work will directly impact call quality, reliability, and customer experience. You’ll move fast, collaborate with customers, and help define the gold standard for AI voice infrastructure. 

Main responsibilities:

• Integration Ownership: Manage and collaborate with customers to support complex SIP integrations with CCaaS/CPaaS platforms like NiCE, Five9, Avaya, Genesys, Amazon Connect, Twilio, and Telnyx, while driving future platform integrations.
• Advanced Troubleshooting: Investigate and debug call failures via PCAP analysis, SIP traces, and carrier logs to improve reliability.
• Enterprise Support Frontline: Act as the primary technical point of contact for enterprise clients post-onboarding.
• Product Advocacy: Translate customer technical feedback and friction points into actionable product improvements for our development teams.

JOB REQUIREMENTS

Skills & Qualifications:

• Have 5+ years as a Telephony Engineer, VoIP Engineer, or equivalent low-latency networking role.
• Have deep understanding of the SIP Protocol (RFC 3261), RTP (media) debugging voice quality issues with PCAPs and trace tools such as Wireshark/TShark.
• Strong Networking fundamentals.(TCP/IP/TLS, DNS, Firewalls).
• Familiarity with modern CPaaS/cloud communication platforms (e.g., Twilio, Plivo, Telnyx).
• Ability to write or modify basic scripts (e.g., Python, Bash, JavaScript). Automate routine troubleshooting tasks.
• Exceptional ability to guide premium clients through complex setups and communicate technical issues clearly.
• Familiarity with Asterisk/FreeSWITCH/Kamailio or relevant SIP proxy / SIP servers is a plus.

Compensation and Benefits

• Competitive salary of up to $2500 USD/month. 
• Remote work arrangement, allowing for flexibility and comfort. 
• Chance to enhance English language skills through interaction with native speakers.
• Attractive Benefits: social insurance from probation period, private healthcare insurance, quarterly bonding, summer trip, company trip,…
• Opportunity to work within a professional and multicultural environment.

CONTACT US

Website : www.nsc-software.com   

Linkedin: www.linkedin.com/company/nscsoftware

Email     : [email protected] 

HQ       : Level 22, PVI Tower, Pham Van Bach, Cau Giay, Hanoi, Vietnam

US       : 4245 N Central Expy, Dallas, Texas 75205

AU       : L24, Three International Towers, 300 Barangaroo Avenue, Sydney NSW 2000

HCM    : L10, Five Star Tower, 28 Bis, Ho Chi Minh, Vietnam