Use navio2 by sensor

hello,
My situation is that :

(Raspberry + Navio2 + 4g Lte Stick : MAVproxy) ----- udp using ddns ---- (laptop : mission planner)

i try this on Raspberry pi by using MAVproxy :

sudo mavproxy.py --master=udp:127.0.0.1:14550 --out=udp:“yourdns.noip.com”:14550 --nodtr

but if my GCS(laptop using Mission Planner) try to connect my pi,

pi said

waiting for heartbeating
mav>

forever…

somebody help me!