FAX over VOIP some times can be challenging. Finding the right configuration is sometimes difficult as it can be SCCP, MGCP, SIP or H323 or even combination of multiple protocol. More over, it can be fax pass-through, T38 or Cisco fax relay. 3rd party Fax Server in the IP side makes the situation a bit difficult.
I've created a project to find the working configuration of FAX in different combinations which is running on your network. Submit your topology and requirement along with protocol to use, we will test in lab. We will submit the configuration along with debug and troubleshooting tips for your reference if something goes wrong.
Click Hereto check the progress and submit your requirement. Hope this will help you.