A node that configures a spanning tree over a network to which a plurality of nodes are connected generates a tree after a cost change using another LAN while continuing to operate the tree that existed before the change, and switches the tree that is used for forwarding after the new tree has been stable. These end plates include seat recesses having a coaxially disposed retaining ring establishing an annular terminal lock edge. The display interface then discontinues the successive display of video frames to show a particular video frame corresponding to a selected channel in response to a terminating action by the user. The implementations of the watermark detecting system, described herein, support quick, efficient, and accurate detection of watermarks by the specifically designed watermark detecting system. The plurality of electrical contacts for the blade insures substantial apparatus function even with the loss of one or even a few of the heating elements or contacts.