I have dsl at home, and a 2524 router. It comes with only 1 ethernet port, and two serial ports. I would like to hook it up to my dsl. I was informed that i would need two ethernet ports. So im deciding to buy another 2524 router. But then someone told me that i needed a serial module. I thought all I would need is a db-60 cable and two db-15 transceivers? Is this true.? what would I actually need?