IP Address of Client during FTP

If IntegrationServer 6.x is my FTP server, with an external client FTP’ing transactions into my Server, is there anyway to obtain the IP Address or HostName of the external client? I could not obtain the IP Address/Hostname in my IS-Session object, nor through getTransportInfo when the FTP transaction takes place. Also, my FTP Session doesn’t show an IP/Hostname.

Do I need a 3rd-party FTP library? Any suggestions for such a library?