Dear friend
when you tray to connect from your home yo connct from WLAN local area network with another way you connect from the same subnet
for example your ip camera ip is 192.168.1.5 if camera acces from lan that not mean acces from 3g with the same ip ther is diffrant ip for your router you should know this ip and make dmz server enable on your router and tayp on it your ip camera ip (192.168.1.5) and when you try to connect to your ip camera from 3g or any wlan except your linksys router you should taype your real ip
Not : your realy ip can change if your relode your router so you should talking with your isp about fixed ip
sorry for my poor english andhope that is usefule for you