There are some external factors that might be affecting your Slingbox connectivity. Power outages, electrical storms and physical changes on the local network are among the most common reasons.
First, we recommend you to check the lights status on your Slingbox. If they are blinking, you will need to check and adjust some router settings. The following link will provide you with the information you must check.
If your Slingbox has solid lights, you can reset the Slingbox and run the configuration for Internet Viewing again.
This link will provide you with this information.