VoIP & Telephony
← All servicesVoice infrastructure without legacy telecom overhead. Asterisk specialist for companies that need reliable telephony.
Typical problems I solve
One-way audio: you can't hear them, or they can't hear you
NAT traversal issues, phones won't register
SIP trunk not working, provider giving cryptic errors
Poor audio quality, echo, choppy sound
Phones losing registration, not reconnecting
No failover when primary trunk goes down
Specific
This is what I have experience with and can help you with.
- → Asterisk PBX setup & configuration
- → SIP trunk configuration & troubleshooting
- → One-way audio, NAT traversal, registration issues
- → Call routing, IVR, voicemail systems
- → Multi-tenant PBX architecture
- → Quality of Service (QoS) for voice traffic
Specialist pages
One-way Audio & NAT Troubleshooting
Asterisk one-way audio is almost always a NAT problem. I debug and fix it: SIP ALG, RTP ports, externip/localnet configuration, firewall rules.
FreePBX Setup & Migration
FreePBX installation, configuration, upgrades and migrations. From legacy PBX to FreePBX, or FreePBX to FreePBX on new hardware.
Why VoIP needs a specialist
VoIP problems are rarely what they look like on the surface. A "bad audio" complaint can be a codec issue, a NAT problem, a firewall rule, or an MTU mismatch. Often several at once.
It's not just Asterisk config
Most VoIP issues are network issues. SIP runs over UDP, RTP streams are sensitive to jitter and packet loss, and NAT rewrites break things in ways that aren't visible in the dialplan. Fixing these problems requires understanding the full stack, from the Asterisk dialplan down to the network layer.
Production experience matters
There's a difference between setting up a PBX in a lab and keeping one running in production with hundreds of concurrent calls. I've worked with multi-tenant platforms, carrier-grade SIP trunking, and high-availability setups where downtime means lost revenue.
Methodical troubleshooting
SIP traces, RTP analysis, packet captures at multiple points in the path. I work from evidence, not guesswork. This approach finds root causes, not workarounds that break again next month.
Background & experience
I have hands-on experience managing SIP infrastructure and IP networks that handle millions of phone calls per month. That includes production VoIP at scale: carrier-grade trunking, multi-tenant platforms, high-availability setups.
I run my own Autonomous System (AS202585) with BGP peering at Dutch internet exchanges, so I understand the network layer that VoIP depends on. I'm a board member of NLNOG (Netherlands Network Operator Group) and have given workshops on VoIP and Asterisk at conferences like MCH2022.
No vendor ties, no reseller agreements. Just practical advice on what works for your situation.
Typical engagements
- →Diagnosing one-way audio and NAT issues
- →SIP trunk setup and troubleshooting
- →PBX migrations (FreePBX, Asterisk, Kamailio)
- →High-availability VoIP architecture
- →Capacity planning and performance tuning
How I work
Fixed price for clearly scoped work. Hourly for diagnostics and open-ended troubleshooting. Response same day, often within hours.
Platforms
Protocols
Other services
Need help with voip & telephony?
Get in touch for a no-obligation conversation. Response same day.