PCI compliance, port 443

I am trying to satisfy pci compliance (Trustwave Trustkeeper) for the use of a credit card terminal that is connected to my modem (Att NVG599 & att 250ad configured as UBV IAD) , I explained to trustwave that I do not have a web site that a customer can log on to and order products or enter customer information nor do we store customer information nor credit card numbers on any computer connected to the network. The test for compliance is done thru port 443 which is used by att to connect and or maintain a three line phone system. This SSL certificate appears to be issued by a private Certificate Authority (CA).