Modem + Switch + Airport Time Capsule

We are using the following structure in our network: modem -> switch -> access point We bought Airport Time Capsule. We changed our access point with time capsule, but time capsule not saw network cable. When we changed it with access point again, it worked. When we connect time capsule to access point, it is working. like the following structure: modem -> switch -> access point -> airport time capsule We want to connect airport time capsue to switch, but we didnt understand what is wrong. Our network cables are not cross cable. What we have to do? Thanks.