What is the T.38 protocol and how does Fax by Email work with Hivoox?

Fax transmission may seem outdated, but it is still widely used in many professional and administrative contexts. To make faxing compatible with modern IP networks, the T.38 protocol was introduced to ensure reliable fax delivery over VoIP.

Understanding how this protocol works helps businesses choose the right fax solution and avoid common issues associated with traditional analog fax machines.

What is the T.38 protocol

The T.38 protocol was developed in 1998 to allow fax transmission over IP networks. Unlike traditional faxing, which relies on analog phone lines, T.38 is designed specifically for VoIP environments.

Its role is to convert fax signals into data packets that can be transmitted reliably over the internet, then reassembled on the receiving side. This reduces errors caused by packet loss, latency, or jitter, which can disrupt fax communication when using standard voice codecs.

T.38 is mainly used to enable fax communication between existing fax terminals or fax-capable systems through IP-based infrastructure.

How Fax by Email works with Hivoox

Hivoox uses the T.38 protocol to provide a Fax by Email service that integrates seamlessly with VoIP environments and virtual PBX setups.

This service allows faxes to be handled digitally instead of relying on physical machines.

• Incoming faxes are received and delivered directly by email
• Documents are sent in PDF or other compatible digital formats
• A SIP terminal supporting T.38 can be configured to send and receive faxes

This approach removes the need for traditional fax lines while keeping compatibility with fax-based workflows.

Key advantages of Fax by Email

Using Fax by Email with the T.38 protocol offers several practical benefits for businesses.

• No physical fax machine or printer required
• Access to faxes from anywhere through an email inbox
• Simplified setup using compatible SIP terminals
• Lower operating costs by reducing paper, ink, and maintenance

These advantages make Fax by Email particularly suitable for remote teams, international businesses, and companies aiming to modernize their communication processes.

Compatibility and configuration considerations

To use T.38 effectively, the SIP terminal, ATA, or PBX must explicitly support the protocol. Configuration must also be aligned with the VoIP service to ensure correct negotiation and reliable fax transmission.

In environments where T.38 is not supported end-to-end, Fax by Email remains a dependable alternative, as it removes many technical constraints associated with real-time fax signaling.

Using Fax by Email in a modern VoIP setup

Fax by Email bridges the gap between legacy fax requirements and modern digital workflows. It allows businesses to continue sending and receiving faxes without maintaining outdated hardware.

Through the Hivoox marketplace, businesses can access Fax by Email services and VoIP solutions that rely on the T.38 protocol, along with technical assistance to ensure proper configuration and smooth operation.