MSI MS-6199VA User Manual page 29

The JMDM1 connector is use for the Modem add-on card which supports
the Modem Wake Up function. To use this function, you need to set the
"Resume By Ring" to enable at the BIOS Power Management Setup.
1
JMDM1
Note: Modem wake-up signal is active "low".
Note: To be able to use this function, you need a power supply that
provide enough power for this feature.
(Power supply with 750 mA 5V Stand-by)
5
PIN
1
2
3
4
5
SIGNAL
NC
GND
MDM_WAKEUP
NC
5VSB
2-24