E212
is an Ethernet tributary board has 12 input in the level of 10G , it also support L2 functions ( like MAC ,VLAN Switching and creating ELINE , ELAN ) and then it forwards packets to the cross-connect to aggregate services to a higher Ethernet level .
When using Ethernet tributary board like E212 . That means you must forward the input ethernet signal to Ethernet Line boards or universal line board.