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
Blog
Guides, technical deep-dives, and industry insights.
Latest
SIP 503 Service Unavailable: Causes, Diagnosis, and Fix
SIP 503 Service Unavailable means a server can't handle your call right now. How to find which element sent it, why it happens, and how to fix each cause.
sipsip-503response-codestroubleshootingsip-trunking
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
Microsoft Teams Call Quality: Prove Whether It's Actually Your Network
Teams call quality issues almost never mean slow internet. How to read Call Health, isolate choppy audio to a fault domain, and prove it with real numbers.
microsoft-teamscall-qualitytroubleshootingjitterpacket-lossremote-work
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
Most Free VoIP Tests Don't Test VoIP
Search for a VoIP test and you'll mostly find speed tests, HTTP timers, and port checks in disguise. How to tell what a test actually measures.
voip-testspeed-testjitterpacket-lossmostesting-methodology
Series
Fundamentals|10 parts
VoIP From the Ground Up
A 10-part series covering everything from how traditional phone calls work to diagnosing VoIP quality problems. Start here if you want to understand voice quality from first principles.
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Guides|12 parts
Getting the Internet Right
A 12-part plain language guide to business internet for people who just want their phones to work. Connection types, SLAs, redundancy, and how to choose the right provider.
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Fundamentals|12 parts
SIP Signaling From the Wire Up
A 12-part series that takes you from understanding what SIP is to reading packet captures and diagnosing real call problems. Covers message anatomy, call flows, registration, NAT traversal, security, trunking, and troubleshooting.
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Troubleshooting|12 parts
When Your Phones Sound Bad
A 12-part VoIP troubleshooting guide covering the most common call quality problems. Symptom-based diagnosis for choppy audio, one-way audio, dropped calls, echo, caller ID issues, and more.
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Guides|8 parts
Moving Your Office Without Losing Your Mind (or Your Phones)
An 8-part guide to moving your business phone system to a new office. Covers ISP selection, building infrastructure, number porting, overlap periods, move day execution, and post-move verification.
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Guides|20 parts
The MSP's Guide to VoIP
A 20-part series for managed service providers adding voice to their stack. Covers business evaluation, network assessment, deployment, ongoing management, advanced architectures, and regulatory compliance.
1234567891011121314151617181920
Guides|10 parts
Your Office Network: The Part Nobody Thinks About
A 10-part series on the internal network layer that makes or breaks your call quality. Covers switches, VLANs, QoS, cabling, routers, WiFi, PoE, and knowing when to upgrade.
12345678910
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
SIP 503 Service Unavailable: Causes, Diagnosis, and Fix
SIP 503 Service Unavailable means a server can't handle your call right now. How to find which element sent it, why it happens, and how to fix each cause.
sipsip-503response-codestroubleshootingsip-trunking
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
Microsoft Teams Call Quality: Prove Whether It's Actually Your Network
Teams call quality issues almost never mean slow internet. How to read Call Health, isolate choppy audio to a fault domain, and prove it with real numbers.
microsoft-teamscall-qualitytroubleshootingjitterpacket-lossremote-work
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
Most Free VoIP Tests Don't Test VoIP
Search for a VoIP test and you'll mostly find speed tests, HTTP timers, and port checks in disguise. How to tell what a test actually measures.
voip-testspeed-testjitterpacket-lossmostesting-methodology
A 60-Second Test Can't Qualify a Network
A clean 60-second VoIP test proves your network was fine for one minute. Real qualification takes a full business cycle. Here's what short tests miss.
voip-testnetwork-qualificationmonitoringintermittent-problemstesting-methodologymsp
The Cost of Bad Call Quality: What Latency Does to a Conversation
Bad call quality costs more than you think. How latency breaks conversational turn-taking, why nobody reports it, and what the talk-over tax costs you.
call-qualitylatencyjitter-buffercustomer-experienceturn-takingmos
How to Tell If a VoIP Test Is Actually Testing VoIP
Most tools labelled a VoIP test measure throughput and little else. Nine tells that give it away, and what a real voice quality test owes you.
voip-testspeed-testnetwork-testingcall-qualitymos-score
The True Cost of a Phone Outage (and How to Calculate Yours)
Phone outage costs go far beyond SLA credits. Calculate what downtime actually costs your business (lost sales, churn, idle staff) with a worked example.
downtimebusiness-continuityslaredundancyfailoveroutage-cost
How Many Concurrent VoIP Calls Can Your Internet Connection Handle?
Calls-per-Mbps math says 100 Mbps carries 1,000 calls. Reality says far fewer. The real limits on concurrent VoIP calls, and how to measure yours.
concurrent-callsbandwidthsip-trunkingcapacity-planningcodecsvoip-quality
SD-WAN and VoIP: What Actually Helps and What's Marketing
SD-WAN vendors promise MPLS-like voice quality over broadband. Here's what the technology genuinely does for VoIP, what it can't fix, and how to test it.
sd-wancall-qualityfailoverqospacket-lossnetwork-architecture
How Call Transfer Works in SIP: REFER, Replaces, and NOTIFY
How SIP call transfer really works: the REFER method, blind vs attended flows, the Replaces header, NOTIFY progress reports, and why transfers fail.
sipcall-transferreferreplacestroubleshootingvoip
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
VoIP Failover in Practice: 5 Architectures Compared
Five VoIP failover architectures ranked by cost and complexity. From simple call forwarding to geo-redundant SIP trunks, with the tradeoffs nobody mentions.
failoverredundancybusiness-continuitysip-trunkingsd-wandisaster-recovery
VoIP Quality Testing: How to Get Real Numbers Instead of 'Calls Sound Bad'
A speed test cannot diagnose VoIP problems. Here is the testing methodology that gives you real jitter, packet loss, and MOS numbers you can use to fix issues and justify changes.
voip-testingmos-scorejitterpacket-losstroubleshootingdiagnostics
QoS for VoIP in Practice: Configuration That Actually Works
Step-by-step QoS configuration for VoIP on Ubiquiti, Fortinet, and Meraki. DSCP marking, queue disciplines, and how to verify it is actually working.
qosdscpnetworkubiquitifortinetmerakivoip-quality
Your Home Office VoIP Checklist: Why Wi-Fi 6 Does Not Fix Call Quality
Wi-Fi 6 and mesh systems do not solve VoIP quality problems at home. Here is what actually matters for reliable calls from a home office, and how to test it.
remote-workwifihome-officevoip-qualitytroubleshootingjitter
Why Caller ID Still Lies in 2026
STIR/SHAKEN was supposed to stop caller ID spoofing. Robocalls barely decreased. Here is why the framework has not delivered on its promise and what businesses can actually do.
stir-shakencaller-idrobocallsspamattestationcompliance
AI Voice Agents Are Calling Your SIP Trunk
AI voice bots generate call patterns that break traditional capacity planning. Here is what changes when automated agents share your SIP trunks with human callers.
aivoice-agentssip-trunkingcapacity-planningcodecsautomation
How to Find the Failing Call in a Huge SIP Trace
Four thousand messages, and one of them matters. A five-step filtering workflow for cutting a SIP capture down to the call you actually need to look at.
siptroubleshootingpacket-capturevoippcap
One-Way Audio: A Packet-Level Walkthrough
A detailed walkthrough of what one-way audio looks like at the packet level. Follow a real SIP call from INVITE to media flow and see exactly where the audio path breaks down.
one-way-audionatrtpsipsdppacket-capturevoip-troubleshooting
Wireshark for VoIP: A Practical Guide to Capturing and Analyzing SIP/RTP
How to capture VoIP traffic with Wireshark, filter for SIP and RTP, extract call quality metrics, and diagnose common problems like one-way audio and codec mismatches.
wiresharkpcapsiprtptroubleshootingpacket-capture
500 Mbps and Your Calls Still Sound Terrible
Fast internet does not mean good VoIP. A 10 Mbps connection with low jitter will outperform a 1 Gbps connection with bufferbloat. Here is why bandwidth is not your problem.
voip-qualitybandwidthbufferbloatjitterlatencyspeed-test
How to Capture VoIP Traffic With Wireshark (and What to Do With It)
Step-by-step guide to capturing SIP and RTP traffic with Wireshark, filtering for VoIP calls, and analyzing the results. Includes where to capture, what filters to use, and how to extract useful data from a pcap file.
wiresharkpacket-capturesiprtpvoip-troubleshootingpcap
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
How Codecs Shape Call Quality
G.711, G.729, Opus, and the other codecs that shape VoIP call quality. How they work, what they trade off, and why the same network sounds different with each codec.
codecg711g729opuscall-qualitybandwidthvoip-fundamentals
Testing VoIP Before You Deploy: A Pre-Flight Checklist
Pre-deployment VoIP checklist: internet quality validation, LAN readiness, firewall rules, DNS, failover, and test call procedures to run before go-live.
voip-deploymentnetwork-testingpre-flightchecklistcall-qualitymsp
How to Disable SIP ALG: A Guide by Router Vendor
Where the SIP ALG control lives on routers from Ubiquiti, Fortinet, SonicWall, TP-Link and others, how to prove ALG was the problem, and what to do when a vendor exposes no supported switch.
sip-algroutertroubleshootingone-way-audionatfirewall
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
Call Recording Laws by State: What Your Business Needs to Know
Federal and state call recording consent laws: one-party vs two-party rules, interstate complications, and what VoIP platforms need to account for.
call-recordingcompliancelegalvoip-securitybusiness-voipregulations
Why Fax, Fire Alarms, and Elevators Resist VoIP
Fax machines, fire panels, elevator phones, and security systems were built for analog circuits. Converting them to VoIP ranges from difficult to tightly governed by life-safety codes.
voip-fundamentalsanalogfire-alarmsecurityfaxmigration
Lines Don't Exist Anymore: How VoIP Changes the Phone System Mental Model
Lines, trunks, key systems, and line appearances don't map cleanly to VoIP. What replaced them, and why the old mental model causes so much confusion.
voip-fundamentalstraditional-telephonysipmigration
VoIP Trunk Capacity: What You Can Actually Verify
How trunk providers engineer shared capacity, what peak-hour degradation does and does not tell you about the cause, and the contract terms to pin down before signing.
sip-trunkingvoip-fundamentalsqualitytroubleshootingcapacity
SIP and WebSockets: How Browser-Based VoIP Works
How SIP over WebSockets enables browser-based VoIP, how the media path works, and how browser softphones connect to traditional phone infrastructure.
sipwebsocketsbrowser-voipvoip-fundamentalssoftphones
What Actually Happens During a Number Port
The mechanics of phone number porting: LOA, LSR, FOC process, how the NPAC routes calls after activation, why ports fail, and how to avoid common problems.
voip-fundamentalsnumber-portinglnptelecompstn
How SRTP Works: Encrypting the Actual Phone Call
How SRTP encrypts VoIP media streams, the three key exchange methods (SDES, DTLS-SRTP, ZRTP), and why encryption failures cause confusing interop problems.
sipsrtpencryptionsecurityvoip-fundamentals
Your POTS Lines Have a Deadline: What the 2026 Copper Shutdown Means
AT&T begins retiring copper in selected areas in summer 2026, aiming to exit most of its copper footprint by the end of 2029. If you still have POTS lines for fax, fire alarms, or elevators, here is what to do before they go dark.
potscopper-retirementanalogfire-alarmmigrationcompliancefax
DNS and VoIP: SRV Records, NAPTR, and Why Phones Fail When DNS Does
How VoIP systems use DNS to find servers, why SRV and NAPTR records matter, and why DNS failures cause some of the most confusing phone outages you will encounter.
voip-fundamentalsdnssiptroubleshootingnetwork-architecture
Why a Speed Test Can't Tell You If VoIP Will Work
Speed tests measure the wrong things for voice traffic. Here are the specific gaps between what a throughput test reports and what VoIP actually needs to sound good.
voip-basicsspeed-testcall-qualityjitterpacket-lossnetwork-testing
What Happens to Your Phones When the Internet Goes Down
Calls drop in seconds when the internet goes down, but VoIP phones need not go silent. See the outage timeline and the failover setup that keeps calls flowing.
voip-basicsbusiness-voipfailoverreliabilityvoip-fundamentals
What Happens When You Press the Call Button
A complete, plain-language walkthrough of everything that happens between tapping a contact on your phone and the other person hearing your voice. Every step, from microphone to speaker.
voip-basicshow-voip-workscall-qualityvoip-fundamentals
Understanding VoIP Packet Loss: What It Means for Call Quality
Packet loss is the most common cause of poor VoIP call quality. What causes it, how to measure it, and how to fix it at each point in the network path.
packet-lossvoip-basicscall-quality
VoIP Quality for Remote Teams: What IT Should Be Monitoring
Remote work put VoIP on home networks where IT has no visibility. Learn what to monitor and how to maintain call quality.
remote-workmonitoringit-ops
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
MOS Scores Explained: The Number Behind Call Quality
MOS is the standard voice quality metric. Learn what it measures, how it is calculated, and what counts as a good score.
mos-scorevoip-basicscall-quality
What Is Jitter and Why Does It Wreck Your Calls?
Jitter causes choppy VoIP calls even on fast connections. Learn what jitter is, how it affects call quality, and how to fix it.
jittervoip-basicscall-quality