BB: Ok ADVA is poets because they are considered 400g outside china. 

The 4 x 100G special solution is listed as Legacy (100G-200G) in POET's product list. The magic permits 100GbE and 200GbE applications to function on a 400GbE switch which is less expensive than running on native 100GbE and 200GbE switches AND it paves the way for those applications to migrate to 400GbE with the 400GbE switches already in place. When ready for the migration, unplug the MicroMux modules and replace with 400GbE modules. 

Note: Adtran delvelops there own OEs. There are two other "Mux" products that uses Adtran OEs. The OI platform provided what Adtran could not do for themselves otherwise they wouild have done so. Perhaps they could but would be inferior and/or too costly.    

Note: GbE (Gigabit Ethernet) = Speed of data movement. Bandwidth is how much data.