Homework 7, due Thu, June 1: Completing the RAP protocol
For this homework, you should complete the implementation of the RAP protocol, adding the generation of DT and AK packets, and the management of the routing table.
When you get a DT packet, you should put some format you decide in the user buffer (I advise you to put, at a minimum, the source node, the length, and the data portion of the packet). You should also generate an AK packet to the sender of the DT packet.
Furthermore, you should implement the management of the route table. For instance, you should age the route table every second, and you should use the reception of AK packets to determine that the route is still valid, thus decrementing its age. When a route's age is too large, you should remove it from the routing table.
Lastly, you should implement the function rap_send_packet for the user to send a packet. The function should work as follows.
- If a route to the destination is already present in the routing table, you should generate a DT packet containing what the user wanted to send.
- If no route to the destination is known, the function should discard the packet, and generate an RR packet to the destination, so that a route can be learned.