At network layer to ensure/implement the security IPSec protocol is used. Each host that is using the IPSec protocol needs to keep a Security Policy Database (SPD). When a packet is to be sent out, the outbound SPD is consulted. Given figure shows the processing of a packet by a sender. Write step by step procedure to explain the working of each step shown in the diagram.

Segment Index Policy Outbound SPD Transport layer ass Drop Policy? pply Index Parameters IPSec layer Outbound SAD IP layer Yes No SA? IKE Datagram