Packet Structure
When A’s data link receives a packet from the network layer, it encapsulates the packet in a frame by adding a data link header and trailer to it
The header is used to store control information. This information consists of three fields:
- Kind : Indicates the type of frames (i.e. data or control)
- SEQ: Store the sequence number which is generated using a circulate between 0 and some maximum
- ACK: Stores number of data frame being acknowledged