NE1NE2NE3 forms a chain network. There are other VC4 services between NE1 and NE3. NE2 is a pass-through site. After the configuration is complete, the NE3 site reports a C2 byte mismatch alert HP-SLM. What are the detection points at this time? (Multiple choice)
A . C2 byte in NE1 sending direction
B . NE2 westbound C2 bytes
C . NE2 eastward C2 bytes
D . NE2 receiving direction C2 byte
Answer: AD