A network system may include a first communication device, a second communication device composed separately from the first communication device and an address database. The first communication device may include a first access device. The first access device may be capable of accessing a network address. The address database may store the network address accessed by the first access device. The second communication device may include a telephone device, an address acquisition device and a second access device. The address acquisition device may acquire the network address from the address database in a case where the telephone device receives an incoming call. The second access device may be capable of accessing the network address acquired by the address acquisition device.