Senior VoIP Network Engineer

Working hours

Monday to Friday, 9am to 5pm. On call rota, 2 weeks in 4.


TTNC’s new office is literally a three-minute walk from Chelmsford train station.

The role

We are looking for a self-starter with at least 5 years experience in technical support within the Telecoms or VoIP industry to help take us to the next level.

Working with our Technical Director, you will advise, lead and coordinate our VoIP Network strategy including defining, deploying and maintaining the company's network edge in-house IP telephony voice communications architecture, as well as associated network connections and hardware components.

You must have a passion for cutting edge technology, a desire to learn and be able to work independently as well as collaboratively.

Role summary

  • Security: Developing, securing and maintaining our public facing voice network.
  • Interoperability with customers, carriers and VoIP application servers.
  • Carrier Capacity planning & Optimising signalling and voice traffic flow inbound and outbound.
  • Overseeing and managing VoIP support related issues.
  • Writing Support and Procedure Diagrams, and Documentation.
  • Ensuring best practices are adhered to, along with regulatory requirements.
  • Maintenance and support including On call rota, 2 weeks in 4.

Key skills

  • 3+ years of experience in Kamailio/OpenSIPS or other related VoIP technologies.
  • Familiarity with open source network tracing tools such as Wireshark/tshark and Ngrep.
  • Strong practical knowledge in Linux admin and Bash shell scripting.
  • Proficiency at operating in a pure Linux environment.
  • Expert Knowledge of SIP, RTP, TCP/IP, NAT, WebRTC and Packet Analysis.
  • Experience in working with Radius.
  • Experience deploying VoIP solutions in a highly available service provider environment.
  • Ability to troubleshoot IP networks for VoIP related problems

Other skills (desirable)

  • Knowledge of FreeSWITCH & Asterisk (configuration & application).
  • Software development experience in Lua.
  • Knowledge of RDBMS (PostgreSQL) & NoSQL (etcd, Redis).
  • Knowledge of software defined networking.
  • Experience in using Docker.

Salary and benefits

The salary is based on experience and skill-set.

We’ll provide you with a new laptop of your choice (high spec Mac Book Pro, Windows or Linux machine) plus 2 decent LCD monitors, as well as any other office equipment you need.

Then there’s also all of this:

  • Quarterly bonuses
  • 4 Weeks Holiday per year + Extra holiday for birthdays & work anniversary
  • Company contributed pension
  • Refer-a-friend scheme
  • Childcare vouchers
  • Bike to work scheme
  • Free tea and coffee
  • Free food on Fridays
  • Technology loans
  • Discounted legal services
  • Employee Assistance Programme (EAP)

How to apply

If you’d like to apply for a position listed, please email with a copy of your CV and a brief covering letter introducing yourself.

If your application is successful, we will contact you within 7 days for an informal telephone interview.

Unfortunately it’s not possible to respond to all applications. If you do not hear from us within 7 days, your application has not been successful.