To determine whether a connection request will have the source address translated, the following parameters can be used: the client's router's IP address, the client's IP netmask, and the client's IP address. The client's router's IP address helps in deciding if NAT (Network Address Translation) is necessary based on routing rules. The client's IP netmask is required to understand the network size and range, which is crucial in determining the translation of addresses within subnetted networks. Lastly, the client's IP address itself is the primary factor in determining if translation is required, as NAT typically changes the source address of packets.