In cascading mode, the total client service rate for each TOM board must be less than or equal to 2.5Gbit/s. But in non-cascading mode, the total client service rate for each TOM board must be less than or eqqual to 10Gbit/s.    

When working in cascading mode, each TOM board cam map a maximum of eight client service into one ODU0/ODU1 signal. But in non-cascading mode maximum four client service can be mapped ino one ODU0/ODU1 signal.