Asterisk / FreeSWITCH Engineer

We are seeking an experienced Asterisk / FreeSWITCH Engineer to join our team and support multiple telephony projects for international clients.
The role requires deep expertise in Asterisk/FreePBX and FreeSWITCH, as well as hands-on experience with WebRTC/webphone integrations and call center environments.

Responsibilities

Project 1: Asterisk/FreePBX IVR System

• Configure and maintain FreePBX with multiple extensions.
• Implement IVR menus that route calls to the appropriate extensions.
• Integrate and troubleshoot our proprietary webphone (WebRTC, SIP over WebSockets).

Project 2: Call Center (FreeSWITCH-based)

• Deploy, configure, and optimize FreeSWITCH for large-scale call center operations.
• Manage SIP trunks and call routing for high-volume call flows.
• Ensure scalability, reliability, and call quality across distributed systems.

General Duties

• Integrate and manage SIP trunks (Flowroute and others).
• Monitor and troubleshoot VoIP traffic (SIP/RTP/WebRTC).
• Configure STUN/TURN servers for WebRTC connectivity.
• Optimize performance for high concurrency environments.
• Maintain Linux servers (Debian/Ubuntu/CentOS).
• Implement security best practices (fail2ban, TLS/SRTP, IP whitelisting).
• Use tools like asterisk CLI, fs_cli, sngrep, tcpdump, and wireshark for debugging.

Required Skills & Experience

• 3+ years of hands-on experience with Asterisk/FreePBX (dialplans, IVRs, queues, extensions).
• Proven expertise in FreeSWITCH for large call center deployments.
• Strong knowledge of SIP protocol, RTP, NAT traversal issues.
• Experience integrating and troubleshooting WebRTC/webphones (SIP over WebSockets).
• Solid Linux system administration skills.
• Strong debugging and performance optimization skills in high-load VoIP environments.

Nice to Have

• Experience with Kamailio/OpenSIPS for SIP load balancing.
• Familiarity with call recording, reporting, and CRM integrations.
• Knowledge of contact center solutions and workforce management tools.

Job Types: Full-time, Part-time, Contract

Application Question(s):

• What is your expected salary for full-time / part-time on-site setup?
• Our office timings are 1pm to 10pm, Mon-Fri, Location: Nazimabad, will that be feasible to you?
• Describe your experience with Asterisk/FreePBX and IVR setup.
• What’s your experience with FreeSWITCH in high-volume call centers?
• How have you integrated WebRTC or proprietary webphones with PBX systems?
• What tools do you use to troubleshoot one-way audio or SIP call issues?
• Have you worked with Flowroute or other SIP trunk providers?

Language:

• English (Required)

Work Location: In person