G.711 vs. Opus vs. G.722: Does Codec Choice Actually Matter?
G.711, G.729, G.722, and Opus compared for real call quality: bandwidth, MOS, packet-loss resilience, and when codec choice actually matters.
codecsg711opusg722g729call-qualitymos
Technical
Posts in technical.
VoIP Over Starlink: What Works, What Breaks, and How to Fix It
VoIP over Starlink mostly works: latency is fine, CGNAT is the catch. What breaks, why inbound calls fail, and the fixes that make Starlink voice reliable.
starlinkcgnatsatellite-internetnat-traversaljitterrural-voip
Why DTMF Breaks on VoIP, and the Three Ways to Send It
Keypresses that the IVR ignores are almost always a DTMF transport mismatch. The three methods, how they are negotiated, and how to tell which one is failing.
dtmfrfc-2833sip-infortptroubleshootingvoip
Certificate Management for VoIP: The Expiration Time Bomb
VoIP certificate expiration causes silent registration failures, one-way audio, and stalled provisioning. Where certs hide, how they fail, and what to do.
tlscertificatessrtpvoip-securitysip-tlsprovisioning
IPv6 and VoIP: The Transition Nobody Wants to Talk About
Most users now reach Google over IPv6, yet VoIP remains stubbornly IPv4. Why SIP resists the transition, where dual-stack breaks calls, and what to test.
ipv6sipnatdual-stacknat64one-way-audio
RTCP: How Your Phones Already Measure Call Quality
RTCP runs alongside every RTP stream, reporting packet loss, jitter, and round-trip time. What sender and receiver reports contain, and where the data goes.
rtcprtpcall-qualitymosmonitoringvoip-fundamentals
What a Session Border Controller Does (and Whether You Need One)
A session border controller sits between your phone system and the internet. What SBCs actually do, how they differ from SIP ALG, and who really needs one.
sbcsession-border-controllersip-trunkingvoip-securitynat-traversalsip
SIP ALG: The Router Setting That Breaks Everything
SIP ALG rewrites VoIP signaling as it crosses your router and almost always makes things worse. How to check if it is enabled and what to do instead.
sip-algnatroutertroubleshootingfirewallvoip-problemsnetwork
How T.38 Fax Actually Works
How T.38 fax relay works, how it differs from fax passthrough, the SIP re-INVITE flow that sets it up, and why T.38 still breaks so often in production.
t38faxfax-over-ipsipvoip-fundamentalstroubleshooting
What a Packet Capture Actually Tells You About a Bad Call
Using Wireshark and packet captures for VoIP troubleshooting: where to capture, what to look for in SIP and RTP streams, and connecting packets to symptoms.
packet-capturewiresharkrtptroubleshootingcall-qualitynetwork-analysis
Wired vs. Wi-Fi for VoIP: Why the Cable Still Wins
Wi-Fi introduces real problems for voice. What actually degrades calls, why contact centres should stay wired, and how to make wireless work when you must.
wifinetworkvoip-basicscontact-centerjitter