How many E1 in STM-4?

1E1=2.048Mbps

STM1=63 E1...

AND STM4=4*STM1=63*4E1s

bUT ITS NOT THAT EASY...

In SDH there is a lot of header data...

STM1 =155.52Mbps

STM4=622.08Mbps

STM16=2488Mbps

STM64=9953Mbps....