Senior VoIP/ Unified Communications Engineer
We are looking for a Senior VoIP / Unified Communications Engineer to design, deploy, and support a centralized VoIP phone system for six retail locations in the United States.
The role is highly hands-on and requires strong production experience with Asterisk or FreeSWITCH, US telephony, SIP infrastructure, networking, and multi-location environments.
The initial stage will focus on architecture and deployment, with an opportunity for ongoing maintenance and further development.
About the project
Each location will have its own:
- US phone numbers / DIDs
- Extension range
- Outbound Caller ID
- Business hours and holiday schedules
- IVR
- E911 emergency address
Employees must also be able to call extensions across locations.
The VoIP platform will be centrally managed and integrated with CRM systems.
Responsibilities
- Design and document the VoIP architecture
- Recommend and deploy Asterisk / FreePBX or FreeSWITCH / FusionPBX
- Configure 6 locations as separate sites or tenants
- Configure local and cross-location extension dialing
- Configure US DIDs, SIP trunks, inbound/outbound routing and Caller ID
- Implement E911 and per-location emergency addressing
- Configure IVRs, ring groups, queues, voicemail, call recording, business hours and holidays
- Provision IP phones and softphones
- Troubleshoot SIP, RTP, NAT, codecs and one-way audio
- Review network requirements: VLAN, QoS, PoE, firewalls and Internet failover
- Implement security against toll fraud, brute-force attacks and unauthorized registrations
- Set up monitoring, alerting, backups and disaster recovery
- Maintain technical documentation and train internal administrators
- Provide post-launch support
Requirements
- 4+ years of hands-on production VoIP experience
- Strong production experience with Asterisk or FreeSWITCH
- Strong knowledge of SIP, SDP, RTP, NAT and codec negotiation
- Experience with sngrep, Wireshark and packet captures
- Strong Linux and networking skills
- Experience with US SIP trunk providers and DID routing
- Experience with multi-site or multi-tenant VoIP environments
- Experience with monitoring, backups, PBX security and disaster recovery
- Strong written technical documentation skills
- Ability to communicate technical decisions clearly in English
Availability to overlap with US business hours
Nice to have
- Experience with UCaaS / CCaaS, hosted PBX, CPaaS or telecom SaaS
- Experience with call-center or automotive/dealership products
- Telephony integration with CRM, APIs and webhooks
- Experience with FusionPBX, Kamailio, OpenSIPS, SBCs or RTPengine
- Experience with Telnyx, Bandwidth, Twilio, Flowroute or similar US carriers
- Knowledge of E911, STIR/SHAKEN, CNAM and caller reputation
- Experience with Yealink, Poly or Grandstream provisioning
- Experience with SMS/MMS and A2P 10DLC
- CDR, call events and call-recording storage
- Bash, Python or Node.js
- High Availability / Disaster Recovery experience
Previous experience working for a VoIP, UCaaS, contact-center or telecom company serving the US market
Work format
Remote
The project is focused on the US market, so partial overlap with US business hours is required.
We are looking for a specialist who can take ownership of the technical solution from architecture and deployment through launch and ongoing support.