How to transfer files between 2 XP with 2 LAN cards each?

We have two DSL routers at the office, 192.168.0.1 and 192.168.1.1 each with different DSL connections. On one, the router is gigabit ethernet and the cards are compatible. However, we are using Netbeui. Is there a way to transfer files and force use of the faster connection? Or, should we use TCP/IP and routing?