Summary: This role involves hands-on support and evolution of hosted VoIP and unified communications platforms, focusing on FreeSWITCH, FusionPBX, and SIP-based telephony. Highlights: 1. Support and evolve hosted VoIP and unified communications platforms 2. Engage in real-world troubleshooting and secure VoIP deployments 3. Work with modern, privately hosted VoIP infrastructure **Job Title:** VoIP System Administrator **Department:** IT Managed Support Services **Location: Mexico City** **Mexico’s SAT**: Registered with (Tax Administration Service). Should have a Mexican RFC tax ID. **Position Type:** Full\-Time **Language**: Fluent English (Required) **Currency**: Paid in MXN **VoIP System Administrator (FreeSWITCH / FusionPBX)** **Location:** Remote (Mexico) **Experience Level:** Intermediate (4–6 years) **About the Role** We are looking for a **VoIP System Administrator** to support and evolve our hosted VoIP and unified communications platforms. This role is ideal for someone who enjoys working hands\-on with **FreeSWITCH, FusionPBX**, and SIP\-based telephony, while also engaging in **real\-world troubleshooting**, customer onboarding, and secure VoIP deployments. You will be responsible for managing production VoIP environments, supporting customer phone systems, deploying IP phones remotely, and collaborating with networking and security teams to ensure high availability, performance, and call quality. **Key Responsibilities** * Administer, maintain, and monitor **FreeSWITCH / FusionPBX** or equivalent VoIP platforms * Configure and support **multi\-tenant VoIP environments** * Provision, configure, and remotely deploy **Yealink IP phones** (and similar vendors) * Manage SIP trunks, extensions, dial plans, call routing, IVRs, voicemail, and failover * Troubleshoot call quality issues (latency, jitter, packet loss, echo) * Perform **packet analysis using Wireshark** to diagnose SIP/RTP issues * Work closely with firewall and network configurations (NAT, SIP ALG, port forwarding) * Assist with customer onboarding, migrations, and VoIP cutovers * Monitor system health, logs, CDRs, and service availability * Document configurations, procedures, and customer deployments * Participate in incident response and service restoration when required **Required Technical Skills** * Hands\-on experience with: + **FreeSWITCH** + **FusionPBX** (or strong FreeSWITCH\-based systems) * Strong understanding of: + SIP, RTP, UDP/TCP + NAT traversal and VoIP firewall rules * Experience deploying and managing: + **Yealink IP phones** (Auto\-Provisioning, firmware, templates) * Network troubleshooting skills: + VLANs, QoS, firewalls, VPNs + Packet capture and analysis using **Wireshark** * Linux administration experience (Ubuntu / Debian preferred) * Experience working in MSP or hosted VoIP environments **Nice\-to\-Have Skills** * Experience with: + Kamailio or OpenSIPS + SBCs and SIP security hardening * Knowledge of: + TLS / SRTP + Multi\-region VoIP deployments * Exposure to: + Cloud or private data center environments + Monitoring tools and alerting systems * Previous customer\-facing or managed services experience **Soft Skills \& Attributes** * Strong troubleshooting mindset and attention to detail * Comfortable working independently and in small technical teams * Ability to explain technical concepts to non\-technical users * Organized, documentation\-driven approach * Calm under pressure during service incidents **What We Offer** * Opportunity to work with **modern, privately hosted VoIP infrastructure** * Exposure to **enterprise and regulated environments** * A technical, no\-nonsense engineering culture * Competitive compensation based on experience