Lasantha Indika A.

I am a Senior Linux Systems Administrator and VoIP Engineer with 20+ years of experience in the ICT industry, delivering Linux infrastructure, VoIP systems, networking, cloud platforms, and enterprise support solutions for global clients. I have worked with state-owned telecommunication providers, Internet Service Providers, international ICT companies, and system integrators as a Support Engineer, Solutions Architect, Solutions Manager, and Consultant. My strength is solving complex Linux and VoIP problems quickly and reliably — from Asterisk dial plan debugging and SIP trunk integration to FreePBX deployments, proxy servers, cloud systems, and enterprise server administration. I have completed 58+ jobs on Upwork with strong client feedback and repeat clients, especially in Linux administration, Asterisk PBX, FreePBX, SIP troubleshooting, VoIP deployment, proxy servers, and infrastructure support. Clients hire me because I focus on practical solutions, fast troubleshooting, and professional communication. Core Expertise Linux Systems Administration • Ubuntu, CentOS, Debian, RedHat, Fedora, openSUSE • Server installation, migration, optimisation, and maintenance • Mail, Web, DNS, FTP, Proxy, VPN, SSH, Firewall • Apache, Nginx, Squid Proxy, Mail Servers • Performance tuning and troubleshooting • Security hardening and server monitoring VoIP & PBX Engineering • Asterisk PBX / FreePBX • SIP Trunk Configuration & Troubleshooting • Dial Plans / IVR / Call Routing • 3CX Configuration • RingCentral Support • IPPBX Systems • Call Centers / Predictive Dialers • GSM Gateway Integration • SIP to GSM Solutions • Huawei GSM Dongle Integration • PBX migration and support Cloud, Virtualization & DevOps • VMware / Docker / Kubernetes • OpenStack • AWS / Azure / Google Cloud / DigitalOcean • Virtual Servers and Infrastructure Deployment • Backup, Recovery & Disaster Planning Networking & Security • VPN / Firewall / Proxy Solutions • Network Troubleshooting • Security Hardening • Remote Access Solutions Recent Upwork Success ✔ VOIP-Asterisk Dial Plan Expert (Debug) – 5★ ✔ 3CX VoIP Provider Interop Configuration – 5★ ✔ RingCentral Phone System Support – 5★ ✔ FreePBX Setup – 4.9★ ✔ Linux Expert – Python Installation & Libraries – 5★ ✔ Configure Email Server Linux CentOS – 5★ ✔ Squid Proxy Optimisation for Heavy Traffic – 5★ ✔ SIP Trunk Setup for FreePBX – 5★ Client Feedback: “Looking for a Linux expert? Your search ends here. Absolutely professional and to the point.” “Excellent freelancer. Did the work fast and well done. Highly recommended.” “Everything was great. Will hire again.” “Working beyond the scope to complete the job. Can recommend this freelancer.” Why Work With Me • 20+ years of real enterprise experience • Strong troubleshooting and problem-solving skills • Deep understanding of Linux + VoIP combined • Reliable communication and professional delivery • Experience across telecom, SaaS, cloud, and enterprise IT • Ability to handle both strategic consulting and hands-on technical work I understand both the business side and the technical side, which helps me deliver practical solutions—not just technical fixes. Let’s discuss how I can help with your Linux infrastructure or VoIP project.