"Does T38Fax work with HylaFAX Enterprise?"

"Yes. HylaFAX Enterprise is our parent company iFAX Solutions' own fax server product. T38Fax was originally built to solve the SIP trunk problem for HylaFAX Enterprise customers."

"What makes T38Fax different from other SIP providers?"

"We run our own T.38 stack on every call — no outsourcing to upstream carriers with inconsistent implementations. And we insist on ECM error correction being enabled. Most carriers disable ECM to reduce processing load. Without ECM, fax pages can arrive corrupted and neither side knows."

"Is T38Fax HIPAA compliant?"

"Yes. T38Fax is HIPAA compliant and SOC 2 Type II certified. T.38 is a real-time protocol — PHI is never stored in transit. Optional VPN tunnels are available for organizations requiring encrypted transport."

"Can I keep my existing fax numbers?"

"Yes. T38Fax supports number porting from virtually any carrier. We handle the porting process and can advise on sequencing the cutover to minimize disruption to your fax operations."

"How many concurrent fax channels do I need?"

"Each concurrent fax transmission requires one channel. A typical enterprise starting point is 4–8 channels, scaled up from there. We can help you right-size based on your fax server's configuration and call volume."

Power-T.38 for Enterprise

The SIP Trunk Your Fax Server Was Waiting For

Q: "Does T38Fax work with OpenText RightFax?"

"Yes. T38Fax is fully certified for OpenText RightFax. Our network was built around the Dialogic SR140 T.38 stack — the same technology embedded in RightFax — so compatibility is deep, not superficial."

Power-T.38 was engineered from day one for RightFax, HylaFAX Enterprise, GFI FaxMaker, and T.38-capable fax servers. Finally, a carrier that actually understands fax.

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The Problem

Your Fax Server Works Perfectly—Until It Hits a SIP Trunk

You invested in enterprise fax server software because your organization depends on reliable fax. OpenText RightFax, HylaFAX Enterprise, GFI FaxMaker, XMedius—these products have rock-solid T.38 support built in.

So why is faxing over your SIP trunk a nightmare?

Your SIP provider doesn’t understand fax. They’re voice people. When you report fax problems, the advice is always the same:

Slow it down to 9600 bps
Turn off ECM error correction
Fax over IP is inherently unreliable

Here’s what they won’t tell you: they’re wrong about all of it. Your fax server is doing its job. The problem is the carrier.

The Solution

Built By Fax People, For Fax People

T38Fax didn’t stumble into the fax business. Our parent company, iFAX Solutions, has been building fax server software for decades—HylaFAX Enterprise is ours. When our customers needed reliable SIP trunks, we searched everywhere for a carrier we could recommend.

We tested them all. Every major SIP provider. Every carrier that claimed to support T.38.

Not a single one passed.

So we built our own. We partnered with Dialogic, whose SR140 T.38 stack powers many of the world’s most popular fax servers, and engineered a network specifically for fax. We achieved the highest interoperability test scores Dialogic had ever recorded.

Why T38Fax

Four Reasons to Choose T38Fax

Consistent T.38

Our T.38 stack runs on every call. We collocate media gateways inside carrier networks—your fax server talks to our gateways, not some unknown upstream provider. No variable routing, no mystery failures.

ECM Error Correction

Most carriers disable ECM to save processing power. We insist on it. Without ECM, fax pages can arrive corrupted with neither side knowing. The word "facsimile" means exact copy—that requires ECM.

Security & Compliance

SOC 2 Type II certified. HIPAA compliant. Optional VPN tunnels. We never store PHI because T.38 is real-time. When your compliance officer asks questions, you'll have answers.

Premium Support

Fax industry veterans who diagnose with protocol analysis, not superstition. We understand T.30 negotiation, ECM partial page retransmission, and why your fax failed at page 47 of 200. Unlimited support included.

Social Proof

What Fax Server Operators Say

"We've sent several million faxes since migrating to T38Fax, and we've not had a single demonstrable case where faxes fail when using T38Fax but succeed with our previous carrier. Thank you for the outstanding service!"

— GreenFax

"I have worked with T38Fax.com for about a year and a half and moved hundreds of phone numbers to their service. Their service works well with XMedius Fax Server and has reliability and up-time our customers can depend on. I have a 100% success rate working with their helpdesk staff."

— Jon Loane, Senior Engineer, Ray Morgan Company

Compatibility

Certified for the Fax Servers You Actually Use

Our network was built around the Dialogic SR140 T.38 stack—the same technology embedded in many of the world’s most widely-deployed fax server products.

Fax Server Software

OpenText RightFax
HylaFAX Enterprise
GFI FaxMaker
XMedius
Biscom
Concord Fax
Esker
Castelle

Softswitches & IP-PBXs

Asterisk / FreePBX
FreeSWITCH
Cisco CUCM
Avaya
3CX

Not on the list? If your software supports T.38, it should work. Try it free or contact us to discuss your environment.

Buying fax lines for customers? See our Voice Service Providers page for wholesale T.38 offload.

View Provider Solutions

Frequently Asked Questions

: Yes. T38Fax is fully certified for OpenText RightFax. Our network was built around the Dialogic SR140 T.38 stack — the same technology embedded in RightFax — so compatibility is deep, not superficial.
: Yes. HylaFAX Enterprise is our parent company iFAX Solutions’ own fax server product. T38Fax was originally built to solve the SIP trunk problem for HylaFAX Enterprise customers.
: We run our own T.38 stack on every call — no outsourcing to upstream carriers with inconsistent implementations. And we insist on ECM error correction being enabled. Most carriers disable ECM to reduce processing load. Without ECM, fax pages can arrive corrupted and neither side knows.
: Yes. T38Fax is HIPAA compliant and SOC 2 Type II certified. T.38 is a real-time protocol — PHI is never stored in transit. Optional VPN tunnels are available for organizations requiring encrypted transport.
: Yes. T38Fax supports number porting from virtually any carrier. We handle the porting process and can advise on sequencing the cutover to minimize disruption to your fax operations.
: Each concurrent fax transmission requires one channel. A typical enterprise starting point is 4–8 channels, scaled up from there. We can help you right-size based on your fax server’s configuration and call volume.