Hi,
I think 1 E1 has 14 carrer they use 1 for ssbh , 1 Precaution and 12 for channels about in sied 1 E1= 2.048 Mbit/s which is split into 32 timeslots (8 × 8,000 × 32 = 2,048)
32 voise channel or data in PDH they use 0&16 channel for signalingand synchronization
|{0}|1|2|3|4|5|~~~|15|{16}|17|18|~~|31|=125microsec