Freelance VoIP/PBX Engineer (Project-Based)

About the Project

We are looking for an experienced VoIP/PBX Engineer to lead the implementation of a new SIP Trunk solution for our global PBX infrastructure. The selected freelancer will be responsible for evaluating Saudi telecom providers, selecting the most suitable solution, coordinating directly with the chosen carrier, and completing the full SIP Trunk integration into our existing FreePBX/Issabel environment.

This is a short-term project expected to be completed within approximately two weeks.

Key Responsibilities

• Evaluate Saudi telecom providers, including STC, Mobily, Zain , and other available carriers.
• Compare SIP Trunk pricing, commercial terms, technical capabilities, and service offerings.
• Recommend the most suitable provider based on reliability, voice quality, scalability, and cost-effectiveness.
• Coordinate directly with the selected telecom provider throughout the provisioning process.
• Obtain all required SIP Trunk credentials and technical configuration details.
• Configure, integrate, and fully deploy the SIP Trunk within our existing FreePBX/Issabel environment.
• Configure and validate:

Inbound and outbound calling

Caller ID presentation

SIP routing and dial plans

Codec configuration

Call routing and failover

Overall call quality and system performance

• Troubleshoot and resolve any SIP, RTP, networking, or call quality issues encountered during implementation.
• Deliver complete documentation of the final configuration and deployment.

Required Skills & Experience

The ideal candidate has proven hands-on experience with:

• SIP Trunks and carrier integrations, particularly with STC, Mobily, Zain , or other Saudi telecom providers.
• PBX platforms including FreePBX, Issabel, 3CX , and Yeastar .
• SIP routing, dial plans, media paths, failover, and high-availability voice environments.
• Designing and scaling VoIP infrastructure for high call volumes.
• Troubleshooting SIP/RTP issues, including packet loss, latency, one-way audio, NAT traversal, and signaling problems.
• Strong networking knowledge, including:

TCP/IP

SIP & RTP

VLANs

QoS

Firewalls

NAT

• Working directly with Saudi telecom providers throughout the provisioning and implementation process.

Preferred Qualifications

• Previous experience implementing enterprise SIP Trunk solutions in Saudi Arabia.
• Ability to independently deliver end-to-end SIP Trunk deployments.
• Strong problem-solving skills and excellent communication.

Project Details

• Duration: Approximately 2 weeks
• Start Date: Immediate
• Location: Remote