i have a CME 2801 router. It has 2 FXS ports and Two FXO ports... if i want to configure these ports how do i do it. in other words if i have to assign an ip address to an ethernet port on my 2801 i give the command int fastethernet 0/1 and then i can make configuration for that interface. but if i have t make any such change to these ports how to i refer to them. exaple if i connect an analog phone directly to this FXS port and i have an ip phone connected and registered with CME how can i call from this ip phone to an analog phone connected on the FXS interface.