Esthiver T

SIP Trunk Setup & PBX-Carrier Integration for Call Center

Fiverr • Freiberufler

Mar 2026 - Present • 6 mos

My client operated a call center and needed their PBX system properly connected to a SIP trunk provider to enable reliable inbound and outbound calling. Before I got involved, their carrier connection wasn't configured correctly, causing issues with call setup and preventing the system from working as intended. I configured the SIP trunk connection between their PBX and carrier, setting up the correct authentication, codecs, and network parameters to establish a stable link. I also handled the firewall and NAT configuration to make sure calls could route properly without one-way audio or dropped connections, and tested inbound/outbound calling across multiple scenarios before handing it off. The result: the call center's PBX was fully connected to their carrier with stable, reliable calling in both directions, giving their agents a working phone system they could depend on. Want me to adjust any of the specifics, like adding details on the exact PBX platform (3CX, FusionPBX, etc.) you connected the trunk to, if you remember?

VoIP & Telephony Systems Engineer

Real Estate Instruct • Freiberufler

Jan 2026 - Mar 2026 • 2 mos

Worked as a VoIP and telephony systems specialist, designing, deploying, and maintaining phone systems for real estate ranging from small call centers to multi-location enterprises. Configured and managed platforms including 3CX, FusionPBX, VitalPBX, RingCentral, MagnusBilling, and Vicidial, along with SIP trunking and Twilio API integrations for automated communication workflows.