Ruben Sierra

VoIP & Network Infrastructure Engineer

Open to offers · Member since 13 Jul 2026

Message

Location: United States

Desired salary: Unspecified

Work preference: Remote Only / Full Time

Experience level: Senior

About

Professional summary

I am a senior systems engineer with more than 28 years of experience building and operating corporate and carrier-grade VoIP and network infrastructure.

My background includes designing telecom architectures from legacy voice systems to wholesale platforms, with hands-on responsibility for high-volume international routing and production environments.

I specialize in Mobile VoIP, real-time communications, Asterisk clustering, SIP-based systems, and secure media transport using SRTP/DTLS. I have also worked extensively with signaling and telephony technologies such as SIP, H.323, SS7, PRI, E1/T1, FXS/FXO, and DTMF.

A major part of my career has focused on infrastructure reliability, packet inspection, latency reduction, and performance monitoring using tools like SolarWinds, Wireshark, Homer, and Zabbix.

I have led and supported remote and distributed telecom operations, including satellite VSAT environments, call center architectures, and wholesale voice termination platforms serving large traffic volumes.

I am currently focused on 100% remote global engineering opportunities where I can contribute deep VoIP, networking, and infrastructure expertise to complex communication systems.

Skills

28 capabilities

Experience

Career history

VoIP & Infrastructure Engineer / Co-Founder URBANODriver

Mar 2025 – Present

Architected and engineered the telecommunications and voice infrastructure for a regional ride-hailing mobile platform. Developed a high-availability Mobile VoIP architecture using PJSIP and Linphone SDK with SIP and FlexiAPI WebRTC extensions under SRTP/DTLS encryption. Designed a 9-station Asterisk-based call center with dynamic queues, IVR, call recording, and agent performance reporting. Managed telecom metrics and backend deployments using Node.js, Docker, and PostgreSQL.

VSAT Internet Provider & Field Network Engineer Globalnetworks360

Jan 2015 – Jan 2025

Designed, deployed, and operated 23 remote VSAT satellite stations based on the iDirect platform in mission-critical environments. Implemented TDMA multiplexing strategies for voice traffic over high-latency satellite links. Maintained 24/7 communications uptime by configuring Asterisk servers and using SolarWinds and Wireshark to reduce packet loss, jitter, and MOS degradation.

VP of Interconnections / Infrastructure Architect OGIS IP Telecom

Jan 2009 – Jan 2014

Designed and scaled the company's wholesale VoIP infrastructure from the ground up. Administered Softswitch Mera II, Cisco AS5350 chassis, Asterisk clusters, and Quintum gateways. Architected integration of Quintum Tenor AXM2400 systems to bridge digital and analog networks. Scaled operations to 250,000 minutes per day while improving ASR and ACD performance.

Network & VoIP Administrator Globalnet Venezuela

Jan 2004 – Jan 2009

Managed carrier-grade voice infrastructure after a corporate merger, handling traffic scaling up to 1,000,000 minutes per month. Administered VoIP routing engines, Cisco access nodes, Quintum Softswitches, and Mera MVTS platforms in Linux environments. Designed and engineered long-range point-to-point MikroTik wireless networks and infrastructure optimization routines.

Network Administrator Planetelecom

Jan 2000 – Jan 2004

Managed international voice termination operations over VoIP gateways including Multitech, Quintum Tenor, and Cisco AS5350 platforms. Led network transitions that increased daily traffic metrics from 20,000 minutes per day. Provided advanced level-3 technical support for interconnected global voice carriers.

Education

Learning history

Fermin Toro

1992

Bachelor’s Degree, Systems Engineering (Computer Science)

Bachelor’s degree in Systems Engineering with graduation concluded in 1992.

Cisco Systems

2004

CCNA, Networking

Cisco Certified Network Associate, legacy status, obtained in 2004.

Cisco Networking Academy

Dates not specified

Certification, Cybersecurity

Introduction to Cybersecurity course with a score of 80/100.

This professional hasn’t added portfolio projects yet.

This professional hasn’t listed any services yet.