Senior VoIP Engineer

About us !

We believe that professional telephony should be simple and intuitive !

How do we do that? By providing « state of the art » communication solutions to optimize your everyday business calls. 

Onoff is a fast-growing SaaS telecom company that provides communication solutions to businesses worldwide. We work hard to provide professionals with an easy-to-use cloud-based-communication system connected to your favorite tools.

Our team of 100 passionate people works from all around the world, with offices in Paris and Tallinn. We provide our employees an environment where they can grow & flourish along with the company. 

Job Description

Responsibilities include:

Setup & maintaining  and configuration of Kamailio & FreeSwitch

    • Analyzing & troubleshooting the SIP traffic
    • Responding to crashes and system failures
    • Enforcing policies around security, compliance, change control, etc


Job details

  • Full-time, permanent contract
  • Location: Paris or Tallinn (possibility of remote working from France or Estonia)

About you !

We expect you to have: 

  • Excellent knowledge of SIP stack
  • Excellent knowledge of FreeSWITCH or Asterisk platforms
  • Experience with working Kamailio/OpenSIPS, or similar
  • Basic programming knowledge, in languages such as Bash, Lua, Python
  • Basic knowledge of WebRTC


Nice to have:

  • Good knowledge of SS7 protocol
  • Good knowledge of SMPP
  • Experience with system and network monitoring solutions
  • Experience with Docker

Recruitement process

  • Interview with Océane, our HR
  • Interview with Dylan, our Team Leader UK

Interested by the opportunity ?

To apply, please click on the link below and send us your CV by email.