I am trying to figure out how many Wildcard TDM400P one can install into a computer without causing any issues like noise and echo. I have a setup where I need to connect 8 outside lines to VOIP server and then connect three analong phones to VOIP server. So basically, I will need to install 2 TDM400P with FXO modules and 1 TDM400P with FXO module. Now some consultant told me that there is a limitation where I can only install two TDM400P PCI cards. If I install the third card, it will create number of issues related to voice quality.
Is it true? Even if I have independent IRQ assigned to each of three cards? Any help or pointer to get more information about this concern is appreciated.