Vladimir K.Private profile: Upwork shows its earnings only to signed-in members, so we check it every few weeks, not daily. MRR here is a rough estimate (Upwork's six-month earnings ÷ months active). Last read Nov 5, 2026.

I am a VoIP Engineer with over 15+ years of expertise in developing, implementing, and optimizing call center systems. Specializing in platforms such as Vicidial (clusters), Asterisk, FusionPBX, and FreePBX, I have a proven track record of delivering end-to-end VoIP solutions that enhance business communications. My work encompasses the entire lifecycle of call center projects, from the initial consultation and requirements gathering to system design, implementation, and ongoing support. I am adept at tailoring solutions based on client needs, whether it’s scaling for larger operations or streamlining for smaller teams. In addition to my VoIP expertise, I have hands-on experience with server management (Linux and Microsoft), Email servers configuration, cloud solutions, and advanced network management, including firewalls, VPNs, and monitoring systems like Zabbix. My knowledge also extends to virtualization with KVM hypervisors and system security with tools such as Fail2ban. I pride myself on providing efficient, reliable, and fully supported systems that meet and exceed client expectations. Let me help you build a call center that works seamlessly with your business operations. Core Competencies: -Call Center Development: Vicidial (clusters), Asterisk, FusionPBX, FreePBX -VoIP and SIP Protocols -Server Management: Linux, Microsoft Server (2003–2016), SBS -Cloud and Email Server Deployment -Network Management: Firewall, Mikrotik, Routers, IPtables, Fail2ban -Active Directory, TCP/IP, DNS, DHCP, VPN, and IPsec Tunnels -Monitoring Solutions: Zabbix (servers and networks) -Virtualization: KVM Hypervisors