 The optical rings transport frames with a bitrate of (approximately) 150 Mbit/s (STM-1/OC-3), 622 Mbit/s (STM-4/OC-12), 2.5 Gbit/s (STM-16/OC-48) or 10Gbit/s (STM-64/OC-192).The frames are divided into 32 kb payload cells that carry the service data from source to destination.Via the OTN management system (OMS), as many cells as required by the service are allocated to connections.