Epson LQ 300+ printer and windows 7 printing issue

I have a terminal server windows server 2007 standard 32 bit. The clients are in the network as well as outside the network of this server. The client which are in the network same as server can print easily using any version of Windows, e.g, xp, 7 but Windows 7 clients outside the network can not print particularly on Epson LQ 300 + printer but Xp client outside the network can print on Epson LQ 300 + also.

Please guide

Regards,

ITalkg