Vyacheslav

Location: Kharkiv, Ukraine Phone:
VYACHESLAV (Remote) [відкрити контакти](див. вище в блоці «контактна інформація»)
Email: Telegram:

KOLODZINSKYI [відкрити контакти](див. вище в блоці «контактна інформація») @kolodzinskiy
LinkedIn: [відкрити контакти](див. вище в блоці «контактна інформація»)
ASTERISK / VOIP ENGINEER | LINUX & NETWORK
SPECIALIST

PROFESSIONAL SUMMARY: Results-driven Asterisk / VoIP Engineer and Linux Systems Specialist with over 4
years of hands-on experience in building, maintaining, and troubleshooting enterprise IP-telephony
infrastructure. Proven expertise in Asterisk dialplan configuration, SIP trunking, call routing optimization, and
backend database integrations (MariaDB/MySQL). Adept at real-time traffic monitoring (SIP/RTP), ensuring
network security via Fail2ban/iptables, and maintaining high system availability under strict SLAs. Possesses
strong analytical skills to independently investigate and resolve complex telephony incidents.

TECHNICAL SKILLS & CORE COMPETENCIES

VoIP & Telephony: Asterisk (4+ yrs) SIP / RTP Dialplans Call Routing SIP Trunks

ARI / AMI Integration Codecs

Monitoring Systems: Zabbix Sngrep Grafana Homer

Linux & Systems Admin: Linux (Ubuntu, Debian, CentOS) Bash Scripting Nginx Docker Automation

Networking & Security: TCP/IP VPN LAN Firewalls Fail2ban ACLs Security Hardening AnyDesk

NetBird TailScale

Databases & Tools: MariaDB MySQL SQL Queries MsSQL Git

Languages: English (B2 / Upper-Intermediate) Ukrainian (Native) Russian (Native)

WORK EXPERIENCE

VoIP Technical Support Engineer Dec 2022 – Present

VoiceSpin Remote

Provide Tier 1/Tier 2 technical support for enterprise telephony infrastructure, maintaining maximum uptime and high
SLA standards.
Troubleshoot real-time VoIP and SIP routing issues, diagnose packet loss, latency, and call quality degradation via
SIP/RTP packet analysis.
Monitor system health and performance using automated Zabbix alerting systems; resolve hardware and software
alerts proactively.
Onboard, train, and mentor junior technical support agents, streamlining incident response procedures across the
engineering team.
Collaborate on maintaining system stability, security configurations, and call routing integrity under high-volume
workloads.

Vyacheslav Kolodzinskyi — Resume Page 1 of 2

VoIP Engineer Aug 2021 – Dec 2022

Bazis LLC Kharkiv, Ukraine

Managed, configured, and optimized core VoIP telephony infrastructure based on Asterisk.
Designed and implemented custom dialplans, connected SIP providers, configured SIP trunks, endpoints, and complex
call routing logic.
Integrated Asterisk with database backend systems (MySQL/MariaDB) for CDRs, call recording management, and user
data routing.
Maintained telephony security using Linux firewalls, Fail2ban, and ACLs to prevent unauthorized SIP brute-force
attacks.
Utilized Bash scripting for routine server automation, automated backups, log rotation, and system health checks.
Monitored network health, database states, and overall system performance using Zabbix to minimize operational
downtime.

Network & System Administrator (Individual Entrepreneur) Aug 2018 – Aug 2021

Triolan Kharkiv, Ukraine

Designed, deployed, and administered Local Area Networks (LAN) and wireless network infrastructure for commercial
and residential clients.
Configured enterprise network hardware, routers, switches, and secure VPN tunnels; performed complete hardware
diagnostics and troubleshooting.
Implemented physical security systems, IP video surveillance installations, and edge routing configurations.

EDUCATION & CERTIFICATIONS

Bachelor's Degree in Radio Engineering / Telecommunications 2014 – 2017
Kharkiv National University of Radio Electronics (KHNURE)

Junior Specialist in Radio Engineering 2010 – 2014
Kharkiv Radio Technical College

EF SET English Certificate — B2 Upper Intermediate Certified

PERSONAL PROJECTS & TECHNICAL INTERESTS

Self-Hosted Infrastructure: Hands-on experience configuring and managing containerized applications (Docker, Nginx,
WebDAV, Nextcloud/ownCloud) on custom home server environments (ZimaOS, Linux Mint).

Open-Source & Firmware Research: Passionate about open-source telephony projects, Linux kernel tweakings, and system
security optimizations.

Vyacheslav Kolodzinskyi — Resume Page 2 of 2