Cisco 1700 Router

Current settings 10TB (NT4.0 SP6) 100.100.100.2 255.255.0.0 – 100TB (W2K Advance Server)192.168.0.2 255.255.255 I can ping from each side of the router to the other side of the router but I can not ping oppossing networks. Why and what can I do toget them to talk?