Fax Rate for Analog to Digital

Team, customer is asking for supporting doc on their fax issue. They worked with support that said "the rate of transmission from analog to digital is currently to fast which causes missed faxes. Please reach out to all suppliers that send you the faxes and request them to manually turn down rate of transmission from 14200 to 9600 to prevent the faxes from failing." ASK: do we have a better work around or documentation for our digital fax requirements that we can share?