No, that port forward rule appears to be for our digital line testing program. It allows use to change some basic settings in the router by default when troubleshooting with a customer. Some of the settings would include, wireless on/off, wep key, and some other basic commands.
If you are having issues with guide coming and going it may just be an issue with the router or the coax in your house. (sometimes the cable card just needs a reload).
If you need additional troubleshooting, feel free to send me a private message.