There is not a standard for ports on a small device like a cable modem or ISDN router. Some are made with Xover ports some are not. Check your docs.
Taking a PC port as a refrence and calling it normal.
Router LAN ports are also normal.
Hub and switch ports are crossed over UNLESS they are labeled as uplink or have an X in which case they are crossed and therefore normal.
Anytime a crossed connects to a crossed or a normal to a normal, you need a crossover cable, otherwise a straight through cable will do.
To make all this simple just plug in a cable, if there is no link light, use a crossover cable...