What is ECM and why is it important?
ECM is an important part of the fax transmission process. This has a direct impact on fax quality, failure rate and other transmission issues that can occur.
The most important part of fax transmission, and one of the most likely culprits of incomplete or distorted fax data or even failures, is ECM. Without ECM all of the data may have been transmitted and confirmed successfully but some of that data could be corrupt which can result in quality issues and even fax failures.
Error correction is imperative for fax transmission as it acts as a checksum of the data being transmitted.
Some fax providers disable ECM either in their system or use telecom providers that don't support it. The reason this happens is that ECM takes a lot more bandwidth and can significantly increase transmission time. With no ECM however, there is no checksum, and even though all the data was transmitted and confirmed, some of that data could be corrupt causing distortion or missing parts of pages or even fax failures.
With no ECM you just get what you get on the other side. A good way to think of this is on a voice call you may hear a little static or get a dropout of voice but the human ear can obviously adjust for these little pieces of missing data. This isn't the case with fax. In fax, this will present itself as lines across a page, garbled or distorted images, or partial pages.
We always have ECM enabled on our system and only use carriers that support it, but if the other side does not or the carrier processing the inbound traffic to their fax number does not, it can cause these issues.
How to know if ECM is enabled or not on the far end?
We do our best to make this information as transparent as possible. To identify if the far end has ECM enabled, please navigate to the history and select the three dots to the right of the fax. From here you can click on the info tab.
This will bring you into the fax details page with lots of great information about the transmission. The field we are looking for specifically is labeled as ECM.
When ECM is showing as 0 this means it is disabled on the far end. When ECM is showing as 256 this means it is enabled.
If you experience these types of issues and are noticing ECM is not enabled for those faxes, it would be best to contact the far end so they can speak with their provider to see if enabling ECM is an option for them.
If you have any questions please contact our support team at support@documo.com.