Most likely port forwarding for your Westell is needed. Follow the instructions very carefully here & setting up a static ip (click on link) is the most important step here so don't miss it. You must do it BEFORE you actually do the port forwarding, else the process won't work: Port Forwarding for the Westell 2100 Wirespeed,
else if that doesn't look like your model then try this one Port Forwarding for the Westell A90-220015-04