Power-T.38 for Enterprise
The SIP Trunk Your Fax Server Was Waiting For
Power-T.38 was engineered from day one for RightFax, HylaFAX Enterprise, GFI FaxMaker, and most other Dialogic SR140 or XCAPI-based enterprise fax servers. Finally, a carrier that understands modern enterprise fax.
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.
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 underwent exhaustive interoperability testing with Dialogic and became one of only a handful of SIP trunk vendors officially certified for use with SR140.
Four Reasons to Choose T38Fax
Consistent T.38
Our T.38 stack runs on every call. We place our 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 certified. HIPAA compliant. Optional VPN tunnels. We never store fax content 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.
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 CompanyCertified 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.
Want the full product picture? See how Power-T.38 is architected — one T.38 stack, gateways inside carrier networks, ECM on every call.
Our Solution: Power-T.38Buying fax lines for customers? See our Voice Service Providers page for wholesale T.38 offload.
View Provider SolutionsFrequently 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 certified. T.38 is a real-time protocol — fax content is never stored in transit. Optional VPN tunnels are available for organizations requiring encrypted transport. See our Security & Compliance page for full details.
- 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.
- A Power-T.38 SIP trunk is elastic, meaning there are no concurrency limits and it will scale to meet demand. Most customers only need one.