Sean Cheesman

Sean Cheesman is a VoIP engineer and network architect with 30+ years of network engineering experience, more than 20 of those years dedicated to designing, deploying, and securing voice systems in production. He has worked extensively with hosted UCaaS platforms, SIP trunking providers, and enterprise SBC deployments across healthcare, financial services, education, government, and multi-site enterprise environments.

His work spans both the infrastructure and application layers of VoIP — from switch-level QoS configuration and SBC deployment to SIP trunk carrier interconnects, STIR/SHAKEN compliance, and large-scale quality monitoring. Across all of it, the work happens at the packet level: diagnosing call-quality problems that look identical from the user's perspective but have completely different root causes on the wire, hardening platforms against the toll-fraud and credential-theft attacks that actually show up in production, and reconstructing incident timelines from raw SIP and RTP archives.

The gap that prompted The VoIP Engineer's Library is the same in every volume: existing resources either explain VoIP protocols from a developer's perspective (useful for building softphones, not for operating production calls) or are vendor-specific configuration guides (useful for one platform, irrelevant for any other). What's missing is a practical, capture-driven approach to VoIP operations — books written for engineers who would rather read the wire than read the documentation.

The capture-driven methodology is the through-line. The same skill that lets you diagnose one-way audio by reading an SDP body also lets you spot toll-fraud reconnaissance in OPTIONS scanning, validate that SRTP is actually encrypting your media, or reconstruct a breach from a HEP archive. Each volume applies that methodology to a different operational discipline.

The Library

Each volume is a self-contained reference for one discipline within VoIP operations. Topology, notation, and packet-capture conventions stay consistent across volumes so a reader who works through both gets a unified mental model of how voice systems actually behave on the wire.

• Vol I — Network Analysis for VoIP Engineers Out now

  The diagnostic discipline. Find and fix problems by reading what the protocols are actually doing — eleven worked case files (one-way audio, registration storms, codec mismatches, T.38 fax failures, transfer zombies, asymmetric loss), a structured five-step diagnostic framework, and an annotated companion library of synthetic packet captures.

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• Vol II — Securing VoIP at Every Layer Forthcoming

  The defensive discipline. The same capture-driven methodology, now applied to attack rather than failure: harden against the attacks that actually hit production, detect the ones that get through anyway, respond when an incident lands. SIP authentication hardening, toll-fraud prevention architectures, SBC security posture, SRTP enforcement, STIR/SHAKEN compliance, and incident-response playbooks — all grounded in what the protocols look like under attack.

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Corrections, feedback, and consulting inquiries: info@seancheesman.com