amsn && Cisco 876

I've been wandering around this site for some time now and every time I type in the url and press the cr I always find myself something new and interesting to read about Congrats for the great site and the great people in here too guys.
I hope that my first post wont be off-topic. Im trying to send stuff for example from 192.168.0.2 to 192.168.0.3 using amsn. With my current configuration, the receiver can not even get the file transfer started. What im trying to do is to have my 876 Router recognize the packets sent FROM hosts inside the lan and are intended FOR hosts inside the same lan and thus, use the full capacity of the network to carry them. Fyi, the amsn port is not standard so i've set it to 8193. Thanks in advance