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I use a fax on my phone line. Can I continue to use my fax?

Fax machines were originally developed for analogue telephone connections. Green Talk is based on VoIP technology (Internet telephony). Fax transmissions can generally work over a VoIP connection, but they are technically more sensitive than with traditional analogue telephone lines.

 

Can I continue using my existing fax machine?

Depending on the device, configuration and receiving party, a fax machine may also work on a VoIP connection. Since fax transmissions over VoIP are more susceptible to disruptions, reliable operation cannot be guaranteed.

Possible effects when transmitting faxes over VoIP:

  • Transmission interruptions
  • Incomplete pages
  • Connection drops
  • Poor transmission quality
  • Compatibility issues between different devices or fax systems

Typical connection variants are:

  • Analogue fax machine connected to the FON port of a FRITZ!Box
  • Multifunction printer with integrated fax functionality
  • IP-based fax solutions via SIP

 

Private customers and SMEs

Green Talk is not specifically designed for operating traditional fax machines.

If you would like to receive or send faxes, using the FaxToMail service is recommended in many cases.

 

FaxToMail

With FaxToMail, you receive faxes directly by email. A separate fax machine is not required.

If you also use an email service from Green, you can send faxes by email as well.

When a fax is received, it is sent to your fax number, accepted by the fax system, converted into a digital document and then delivered by email.

 

Send a fax by email (Mail-to-Fax)

  1. Create a new message in your email program.
  2. Enter the destination phone number with the suffix @fax.green.ch as the recipient.
  3. Example: 0123456789@fax.green.ch
  4. Send the message.

After sending, you will receive a confirmation from the fax system.

This confirmation verifies successful handover to the fax gateway. It is not a delivery receipt or read confirmation from the recipient.

 

Benefits of FaxToMail

  • Select a new fax number or keep your existing fax number
  • Worldwide receipt of faxes directly by email
  • Receive faxes on PC, Mac, tablet or smartphone
  • Free registration and setup
  • Low fixed costs
  • Sender fax number visible in the subject line
  • No separate fax machine required
  • Digital archiving of received faxes
  • No paper or toner costs
  • Worldwide access to received faxes
  • Fax reception independent of paper levels or device malfunctions

 

Fax over VoIP and T.38

The T.38 protocol is often used for fax transmissions over VoIP. It was specifically developed for Fax-over-IP and can improve the reliability of fax transmissions.

If the fax machine or receiving system does not support T.38, transmission is often carried out via the G.711 voice codec. This may work, but is more prone to disruption in many environments.

 

Typical error scenarios

Receiving faxes works, sending does not

  • Incorrect number assignment
  • Issues at the receiving party
  • Incompatible fax protocols
  • Issues with international fax destinations

 

Sending faxes works, receiving does not

  • Fax function disabled
  • Number not reachable
  • Routing problems

 

Only individual recipients are affected

  • Compatibility issues between fax systems
  • Issues at the receiving party
  • Line or quality issues

 

Note: If your fax machine does not work reliably via Green Talk, using FaxToMail is recommended. This helps avoid typical problems associated with fax transmissions over VoIP.

 

SMEs and Business

Green offers VoIP solutions for SMEs and business customers. Depending on the VoIP solution used, an existing fax machine may continue to be used.

Support for fax machines depends on the infrastructure used and the selected solution.

Note: Whether an existing fax machine can continue to be operated with your VoIP solution must be assessed on a case-by-case basis. If you would like to continue using a fax machine, please contact support before switching.

 

Additional information

Information about the installation and configuration of Green Talk:

https://www.green.ch/en/talk-installation-and-configuration

Information about Green Talk settings:

https://www.green.ch/en/talk-settings-in-the-customer-portal

Information about managing Green Talk:

https://www.green.ch/en/talk-in-the-customer-console