3 - X.25

X.25 PCI

Data Qualifier Bit (1 bit)

Delivery Confirmation Bit (1 bit)

'01' Bits (2 bits)

Group Number (4 bits)

Virtual Circuit (1 Byte)

P(r) (3 bits)

More Data Bit (1 bit)

P(s) (3 bits)

F-Bit (1 bit)