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This video will walk you through the steps to disable the high speed Fax over IP features V.34 and Error Correction Mode on your Dialogic IP faxing solution. This video was recorded at 1280 x 720 resolution for high-definition and is best viewed in full screen mode.

V.34 provides the most extensive range of supported data transmission rates allowing it to optimize both speed and reliability over a wide range of line conditions. The V.34 fax page data is transmitted at 33.60kbps twice the speed of V.17 faxing. In addition V.34 uses ECM as a mandatory feature that is designed to handle page transmission error in a much more efficient way. Let’s discuss ECM for a moment. ECM is a mandatory feature for V.34 fax, as opposed to V.17 where it is optional. ECM protocol was designed to automatically detect and correct errors in the fax transmission process caused by factors such as telephone line noise. The page data to be transmitted is divided into small blocks of data called Octets.

Once all Octets are received they are examined using checksums. If any errors in the checksums are detected the receiving fax device signals the transmitting fax device, to retransmit the Octets that were received incorrectly. The transmitter then retransmits only the needed blocks rather than the old page. Once all Octets are received correctly they are ordered and the page data is reconstructed by removing the Octet frames and signalling frames. Generally this results in faster more successful fax transmission than in a scenario where the entire page data is re-transmitted once or multiple times.

Experience in the field has demonstrated that some combination of correspondence of fax machines and systems and V.34 & ECM modes are troublesome. The problems generally appear as cut off faxes during transmission or partial faxes during reception. You will normally disable ECM and all V.34 features together. Different results between differing Brooktrout API versions and different fax hardware may occur and testing may be required in order to get the best results of speed and stability in each environment.

To disable V.34 in RightFax complete the following steps.

Stop the Doc Transport Module in RightFax Enterprise Fax Manager.

Double-click the service to open configuration.

Select your fax board on the left.

Click configure Brooktrout.

The configuration wizard is going to open up. We are going to choose “advanced”.

Click BT call parameters on the left here.

Go to show advanced. In the Advanced settings, select error correction mode and choose ECM disabled.

Next go to the V.34 settings and select disabled for all three.

Make sure you save and apply your settings.

Close the Brooktrout configuration tool. And "ok" to close the Doc Transport Configuration.

Restart Doc Transport. That’s it. Now you are faxing with V.17 faxing with V.34 and error correction mode disabled.

This is Jay Campbell with The Fax Guys from RightFax University saying thank you for watching.