Network seperation

G'day guys,

We have 2 seperate networks and want to run them over one microwave shot. We seem to have problems getting it working. The connections are made properly, and lets say RouterA1 connects to a taclane(KG175 encrytion), then to RouterB1 then over the microwave over to RouterB2 which has another taclane on to RouterA2. We are playing around with accesslists and 'ip route' trying to get things going, as we need to keep them seperate. From the RouterA1 it goes into taclane (has an ip address), and then to RouterB1. Now thru the microwave, (also has an ip address). On the other end the same, microwave to RouterB2, to taclane, to RouterA2. What are all the 'ingredients' to make this work?
And how do we go about protocols which are different on both networks?

Finally got it up. We created a tunnel from RouterB1 to RouterB2 and had no need for anthing else once the kg175 was correctly setup. One of the accesslists let the different ip addresses thru. Now we find that this sucks up a lot of bandwidth of the microwave shot slowing things down drastically, another day goes by......