ACCESS DVR ON WEB

I HAVE A MAJESTY MP-6016 DVR. I AM USING LINKSYS WAG200G ADSL GATEWAY ROUTER. I HAVE DONE THE PORT MAPPING FOR MY DVR AND I AM ABLE TO ACCESS MY DVR ON MY LAN. BUT OUTSIDE LAN I CAN’T. I AM USING A DYNDNS.ORG DOMAIN NAME TO ACCESS DVR ON WEB. COULD ANY BODY SUGGEST A SOLUTION TO SOLVE THIS PROBLEM