A network relay apparatus and method using a software module that easily support various network protocols and new network protocols. The network relay apparatus includes a first modem unit communicating with a first network using a first protocol, a second modem unit communicating with a second network using a second protocol, a bridge unit converting data to be suitable for the first and second protocols when the data is exchanged between the first modem unit and the second modem unit, and a controller generating the first and second modem units and the bridge unit in a software manner.