I am trying to exchange UDP data between my RPi 4b and PC(Laptop) both connected to WLAN and it is working properly. But when I connected RPi to GSM module and PC to same WLAN, the data exchange can’t be proceed and it doesn’t show any error but just hangs up at the client (PC) side. Listened and researched about port-forwarding but after allot of doings I tired and came with no solution. Could some one help me here about port-forwarding and how to do that using GSM?