All of the Suddenlink cable modems that have a single cat5 LAN port are automatically in bridged mode.
All the Suddenlink Modems that have four Cat5 LAN ports are automatically in router mode.
Can the modem Suddenlink provided be changed from the mode described above?
No, Suddenlink supplied modems have configuration files that automatically override any settings that can be changed so they will reset back to the original mode described above.