A treadmill may comprise a deck, a treadbelt covering at least a portion of the deck, and a drive motor configured for driving the treadbelt. Upon receiving a session initiation message at a particular port, the access node forwards the session initiation message to one or more of the access servers based on the configured preferred access server for the particular port. The underlayer is on the material layer. Thereafter, the amorphous silicon film is subjected to heat treatment to cause crystal growth therein.