The NIM-4FXS is a network interface module that provides four FXS ports for connecting analog devices, such as phones and fax machines, to a Cisco router or switch. Each FXS port on the NIM-4FXS is capable of providing up to 100mA of current at 48V DC.
The REN (Ringer Equivalence Number) for each FXS port on the NIM-4FXS is 3.5. This means that each port is capable of supporting up to three analog devices with a total REN of 3.5 or less.
In terms of overall power consumption, the NIM-4FXS has a maximum power draw of 5.4W. This means that the total power draw for all four FXS ports on the module should not exceed 5.4W.