Connecting M8428-K switches from M1000E enclosure to existing brocade fabrics.

Trying to get options for connecting FCOE M8428-K switch to existing brocade fabric . Documentation says we can use them as access gateway and connect two ports - cables from each switch ( from m1000 chassis) to fabric as N_Ports . This way al the devices WWN will be logged in and can be zoned . Other option is turn the switch into full switch fabric mode , does this require licenses , how can we trunk the two ports ? Our fabri version is 6.41 a we have fabric A and fabric B.