One time slot will be used for one LSL & at maximum 16 LSL can be created between same OPC & DPC.
In ISUP protocol there are 16 bits reserved for CIC ( circuit identification code)
Lower 5 bits will identify 32 timeslots in a E1
Next Higher seven will indentify E1 number
Next higher 4 bits are reserve
If 5 bits are 11111 -> 32
If 7 bits are 1111111 -> 128
128*32 —-> 4096 time slots or CIC in a trunk group between OPC & DPC