Fix common fax problems — failed sends, busy signals, VoIP issues, and error codes — with step-by-step diagnostics and prevention tips.
Articles in Troubleshooting
VoIP Fax Solutions: How to Make Fax Work Over VoIP - VoIP fax solutions let businesses keep sending faxes after moving to internet phone systems. Learn the four approaches — T.38 protocol, ATA gateways, fax servers, and cloud fax — and which one is right for your setup.
T.38 Protocol Explained: Everything You Need to Know - T.38 is the ITU-T standard that makes real-time fax transmission possible over IP networks. This deep-dive covers how T.38 works, UDPTL packet structure, redundancy settings, SIP re-INVITE negotiation, and when to use T.38 versus G.711 or cloud fax.
Fax With VoIP: Everything You Need to Know - Faxing over VoIP is notoriously unreliable — but it can work with the right setup. This guide covers why VoIP breaks fax signals, the T.38 fix, three practical methods, step-by-step configuration, and when cloud fax is the smarter choice.
Fax Modem: What It Is, How It Works & Modern Alternatives - A fax modem lets a computer send and receive faxes over a phone line — no fax machine required. Learn how fax modems work, the T.30 protocol behind every fax call, and why most people have switched to online fax services.
VoIP Fax Gateway: Everything You Need to Know - A VoIP fax gateway bridges your analog fax machine and IP network — fixing the packet-loss failures that make standard VoIP faxing unreliable. Learn how T.38 works, which device to buy, and step-by-step setup.
Fax Machine Not Working? 10 Common Problems & Fixes - Fax machine not working? Here are the 10 most common fax problems — no dial tone, busy signals, paper jams, VoIP failures — with step-by-step fixes for each.
Fax over IP (FoIP): How It Works & Best Practices - Fax over IP (FoIP) sends fax documents across internet networks instead of phone lines. Learn how FoIP works, the three transmission methods, deployment options, and best practices for reliable IP fax — plus when cloud fax is the smarter choice.
Analog Fax vs. Digital Fax: Key Differences Explained - Analog fax uses phone lines and paper. Digital fax uses the internet and cloud storage. Here's how they compare on speed, cost, security, and convenience — and which one your business should use in 2026.
VoIP Fax Problems: Why Fax Fails on VoIP & How to Fix It - VoIP fax problems are caused by packet loss, codec compression, and jitter. Learn why fax fails on VoIP and 6 proven fixes to get it working — or switch to a more reliable method.
Fax Error Codes Explained: Common Errors & How to Fix Them - Seeing an error code on your fax machine? This guide explains every common fax error code — from communication errors and busy signals to ECM failures — with the exact fix for each one.
T.38 Fax Protocol Explained: What It Is & Why It Matters - T.38 is the protocol that makes fax work over IP networks. Learn how T.38 fax relay works, how it compares to G.711 passthrough, and when you actually need it — plus a simpler alternative that skips VoIP entirely.
How to Find Your Fax Number (4 Methods That Work) - Not sure what your fax number is? Here is how to find it on any setup — HP, Brother, Canon, or Epson printer, or an online fax account — in under two minutes.
Fax Resolution Settings: Standard, Fine & Superfine Explained - Fax resolution determines whether your document arrives crisp or blurry. Learn the DPI specs for Standard, Fine, and Superfine — plus which setting to use for text, handwriting, and detailed graphics.
Fax Busy Signal: Why It Happens & 5 Ways to Fix It - Getting a busy signal when you try to send a fax? Here are the 5 most common causes — from a genuinely occupied line to VoIP conflicts — and the exact fix for each one.
Fax Number Lookup: How to Find Any Fax Number Online - Need to find a fax number for a business, government agency, or doctor's office? Here are 7 reliable ways to look up any fax number online — plus a directory of the most-requested numbers.
Why Is My Fax Blurry? Resolution, Scanning & Fix Tips - Blurry faxes are caused by low resolution settings, dirty scanners, poor document preparation, or phone line noise. Learn the exact DPI settings, scanning tips, and fixes to send crystal-clear faxes every time.
Fax Not Going Through? 8 Fixes That Actually Work - Your fax won't go through and you need it delivered now. Here are the 8 most common reasons faxes fail — wrong number, busy line, VoIP issues, and more — with step-by-step fixes for each one.