I recently retired my Telecom supplied (some years ago) Thomson ADSL modem/router as it was increasingly locking up and needing to be reset on a several times daily basis. 

I have replaced it with a TP-Link TD-W8960N, which I had successfully implemented for someone else and which has had favourable reviews here. However, I now find that my Tivo EPG listings are not updating and attempts to connect to the Tivo service are timing out. The Tivo suggests that I unblock a whole range of ports. I've confirmed that it is the TD-W8960N getting in the way by both putting the old Thomson back and also connecting the Tivo to an Android phone acting as a Wireless Access Point - both of which allow the Tivo to update.

However embarrassingly, I can't even find how to get into the TD-W8960N's firewall settings. Can someone point me in the right direction please.