The best way to check the LED status or purpose is to unplugged all the cables and plugged in one by one and you can also check the user manual of your wireless device .
This is basically a Packet Voice Digital Signal (PVDM) is a hardware module that provides digital-signal-processor (DSP) resources to the system. A PVDM module can be populated with one or more DSPs. The DSP resources on a PVDM module provide collaboration services including voice sessions, transcoding sessions, conference sessions, and video.
Please check the below link for configuration of Ports.