An ATM cell, as defined by the PTI, cannot be:
A.
User data cell
B.
Idle cell
C.
OAM segment flow cell
D.
OAM segment flow cell
E.
RM cell
F.
OAM end-to-end flow cell
G.
AAL2 cell
Explanation:
A 3-bit Payload Type Indicator (PTI) field indicates the type of data being carried in the payload. The high-order bit is a “0” if the payload contains user information and is a “1” if it carries connection management information. The second bit indicates if the cell experienced congestion over a path. If the payload is user information, the third bit indicates if the information is from Customer Premises Equipment. The PTI field is identical for UNI/NNI/STI.