What Fax Equipment Protocols work with VOIP?

When using a fax machine, it is suggested that users connect their fax directly into the VoIP adapter
In addition, users should ensure that an Error Correction Mode (ECM) is disabled on their fax machines as this compounds problems and distortion regarding the compression, decompression, and transmission of data communications through a VoIP provider.
Also the Baud Rate should be lowered to no more than 9600. When faxing, the fax should be set to Standard instead of Photo or Fine.
The problem exists when the 2 connecting fax machines, or in some cases fax modems cannot maintain a consistent handshake. The handshake occurs many times per second and is the method for which each device ensues that the other device is still listening. VOIP communications does not provide a consistently CLEAN connection; therefore during the handshaking noise may be introduced into the call causing either device to assume that the other has hung up. This noise comes from the compression being done to the data stream. Most providers operate on the codec, G.729 which uses lossy compression, which reduces the amount of bandwidth required, but can impact the call quality. Hence, a dropped calls when faxing.
One method of attempting to fix this problem relies on slowing down the handshake in order allow for bad packets to simply fall off the call, and not interfere with the handshake in addition to changing the codec being used to compress the phone call to the G.711, employing no compression schemes, which requires more bandwidth but no call loss.