Hire the Best Kamailio Specialists

I am a VoIP and Telephony Engineer with extensive experience in 3CX, VICIdial, Asterisk, FreeSWITCH, Twilio, SIP Trunking, and DID number provisioning. I help businesses build, optimize, and maintain reliable communication systems for call centers, telemarketing operations, and enterprise telephony environments. My expertise includes PBX installation and configuration, SIP trunk integration, number porting, IVR design, call routing, predictive dialer setup, inbound and outbound call center solutions, and VoIP troubleshooting. I am also experienced with Linux server administration, cloud deployments, and API integrations for voice and SMS applications. Whether you need a complete call center deployment, 3CX configuration, VICIdial optimization, Twilio integration, SIP troubleshooting, or ongoing telephony support, I can deliver scalable and dependable solutions tailored to your business needs. Core Skills: • 3CX PBX Administration • VICIdial Installation & Management • Asterisk & FreeSWITCH Development • Twilio Voice & SMS Solutions • SIP Trunk Configuration • DID Number Provisioning & Porting • Predictive & Power Dialers • IVR & Call Flow Design • Linux Server Administration • VoIP Troubleshooting & Optimization • CRM & API Integrations • Call Center Infrastructure Setup I focus on delivering reliable communication systems that improve efficiency, call quality, and business performance. 3CX, VICIdial, Asterisk, FreeSWITCH, Twilio, VoIP, SIP, SIP Trunk, DID Numbers, PBX, IP PBX, Hosted PBX, Cloud PBX, Telephony, Telecom, Telecommunications, Call Center, Contact Center, Predictive Dialer, Power Dialer, Auto Dialer, Progressive Dialer, Call Routing, IVR, Interactive Voice Response, Call Queue, Ring Groups, Voicemail, Call Recording, Number Porting, SIP Carrier, Voice Gateway, Session Border Controller, SBC, WebRTC, SMS Gateway, Twilio Voice, Twilio SMS, Twilio API, Linux Administration, CentOS, Ubuntu, Debian, Rocky Linux, AlmaLinux, MySQL, MariaDB, PostgreSQL, Apache, Nginx, SSH, VPN, Firewall, Networking, TCP/IP, UDP, RTP, QoS, NAT Configuration, VoIP Troubleshooting, SIP Debugging, SIP Trace, Wireshark, CRM Integration, Salesforce Integration, HubSpot Integration, Zoho CRM, Pipedrive, API Integration, REST API, PHP, Python, Bash Scripting, AGI Scripts, Call Flow Design, Inbound Calling, Outbound Calling, Lead Management, Telemarketing, Cold Calling Systems, Voice Broadcasting, Bulk SMS, DID Provisioning, SIP Registration, Carrier Integration, Call Monitoring, Queue Management, Agent Management, Multi Tenant PBX, Failover Configuration, High Availability, Cloud Deployment, AWS, DigitalOcean, Vultr, Linode, Dedicated Servers, VPS Setup, Server Migration, System Optimization, VoIP Security, Fraud Prevention, FreePBX, Issabel PBX, FusionPBX, Elastix, Yeastar, Grandstream, Fanvil, Yealink, Polycom, Cisco VoIP, Sangoma, OpenSIPS, Kamailio, Voice API, Telecom Consulting, Call Center Setup, VoIP Engineer, Telephony Engineer, SIP Expert, 3CX Expert, VICIdial Expert, Twilio Expert, Asterisk Expert, FreeSWITCH Expert, Linux Server Administrator, Network Engineer, Technical Support, System Administration, Remote Support, Cloud Communications, Unified Communications, UCaaS, Business Phone System, Enterprise Telephony, Call Center Optimization, Dialer Configuration, Lead Campaign Management, Real Time Reporting, Call Analytics, Voice Solutions, Telecom Infrastructure, Contact Center Solutions, VoIP Deployment, PBX Installation, SIP Configuration, DID Management, Call Center Technology, Telecom Solutions

I am a senior VoIP Engineer with over 15 years of experience designing and deploying SIP-based telephony solutions. I have strong hands-on expertise with Asterisk, FreeSWITCH, Kamailio, OpenSIPS, Kazoo, and Jambonz, and I specialize in building reliable, high-availability VoIP systems for production environments. In addition, I have extensive experience integrating SIP call flows with AI voice agents over WebSocket, supporting real-time, bidirectional audio. I have built conversational voice bots end to end, including streaming STT, LLM-based dialog logic, and low-latency TTS, delivering natural and responsive voice interactions. I focus on scalable, secure, and low-latency solutions that bridge traditional telephony with modern AI-driven voice systems.

👋 Hi, I’m Oleksii - a Twilio expert with over 7 years of hands-on experience building scalable, real-time communication systems using the full Twilio stack: 📞 Programmable Voice / SMS, 🧠 TaskRouter & Flex, 🎛️ Studio, Functions, Conversations, Sync, Webhooks and more. I’ve successfully completed 120+ Twilio projects on Upwork, including: • Eliminating latency issues in phone calls 🔧 • Creating SMS marketing automation pipelines 📲 • Developing full-scale Flex dashboards with custom workflows 🧩 Clients describe me as: “Very skilled, excellent communicator, smart guy and a pleasure to deal with.” “Oleksii was very helpful and available :) We no longer have problems with latency during our phone calls.” 🛠 Whether you need help with: • Twilio Studio call flows • Complex webhook-based automation • TwiML, IVR, call forwarding setups • Integrating Twilio with CRMs or internal systems • Building voice/SMS logic in Node.js, Laravel, or Firebase environments …I’ve got you covered. Let’s bring your Twilio-powered solution to life 🚀 Feel free to invite me to your job or message me with questions.

I help U.S. businesses navigate SMS approval, deliverability, and compliance requirements - reducing the risk of carrier rejections, blocked traffic, and regulatory issues. I specialize in A2P SMS compliance and deliverability, including 10DLC registration, Toll-Free Verification (TFN), and TCPA/CTIA consent audits, as well as diagnosing carrier-level delivery problems. My work focuses on aligning SMS programs with current carrier and regulatory expectations so they can operate and scale responsibly in the U.S. market. If your messages are being rejected, filtered, or delayed - or you’re unsure whether your consent flow and use case will withstand carrier or legal review—I can help assess and correct the underlying issues. What I Do • 10DLC brand & campaign registration (new submissions, rejections, reclassifications) • Toll-Free Verification (TFN) setup and resubmissions • TCPA / CTIA compliance audits (opt-in flows, disclosures, opt-out handling) • SMS deliverability diagnostics (carrier filtering, content flags, throughput limits) • Platform-specific guidance (Infobip, Twilio, GoHighLevel, ClickSend, SimpleTexting) • Compliance-aware SMS automation (webhooks, triggers, rate-limiting, quiet hours)

I build, scale and rescue production VoIP and Voice AI platforms. For over 15 years, I've been designing SIP, WebRTC and real-time communication systems built on FreeSWITCH, OpenSIPS, Asterisk and related technologies. My experience ranges from troubleshooting complex SIP and media issues to designing multi-tenant communication platforms, AI-powered voice systems and carrier-grade telephony infrastructure. I can help with: • AI Voice Agents and Voice AI Platforms • OpenAI Realtime, Gemini Live, Deepgram, ElevenLabs, RetellAI • FreeSWITCH and Asterisk development • OpenSIPS and Kamailio SIP routing • SIP trunking and carrier integrations • WebRTC platforms and browser telephony • RTP, NAT traversal and media troubleshooting • SBC design and deployment • Contact center and call center solutions • Twilio, Telnyx and CPaaS integrations • Production incident investigation and VoIP troubleshooting • Telephony migrations and system modernization My technical background includes: • VoIP: SIP, RTP, WebRTC, FreeSWITCH, OpenSIPS, Kamailio, Asterisk, Jambonz, Drachtio, Twilio, Telnyx • Backend Development: Node.js, TypeScript, Python, Go, C • Databases: PostgreSQL, MySQL, MongoDB, Redis • Messaging: RabbitMQ, AWS SQS • Cloud & Infrastructure: AWS, GCP, Docker, Kubernetes, Linux, CI/CD • Monitoring: Prometheus, Grafana, ELK Stack Recent projects include: • AI-powered voice agents integrated with telephony platforms • SIP and WebRTC infrastructures handling production traffic • Multi-tenant communication platforms for SaaS products • Carrier integrations and custom call routing solutions • Real-time communication systems built on FreeSWITCH, OpenSIPS and cloud-native infrastructure Whether you need to build a new platform, migrate an existing system, integrate Voice AI capabilities or resolve complex SIP/WebRTC issues, I can help deliver a reliable production-ready solution.

Helped businesses deploy Microsoft Teams Phone, Genesys Cloud CX, SIP Trunks, and AudioCodes SBC solutions, reducing telephony issues and improving call reliability for contact centers and enterprise environments. Specialized in Microsoft Teams Phone, Genesys Cloud CX, SIP Trunking, and AudioCodes SBC with experience delivering cloud voice and contact center solutions for SMB and enterprise customers. 🔹 Microsoft Teams & Voice Solutions ✔️ Microsoft Teams Direct Routing ✔️ Operator Connect & Calling Plans ✔️ Auto Attendants & Call Queues ✔️ PSTN Integration & SBC Configuration ✔️ Multi-provider SIP failover routing 🔹 VoIP & Contact Center Expertise ✔️ SIP, E1, PRI integrations ✔️ AudioCodes SBC configuration & troubleshooting ✔️ Genesys Cloud CX (BYOCC, SIP Trunks, Routing) ✔️ Call recording & voice security ✔️ VoIP troubleshooting (RTP, TLS, SRTP, QoS) 🔹 Cloud & Infrastructure ✔️ AWS & Azure deployments ✔️ Hybrid cloud architecture ✔️ VPNs, Firewalls, Load Balancers ✔️ DNS, SPF, DKIM, DMARC & Email deliverability ✔️ High-availability & secure network design