a. Recall that when a peer has a matching file, it sends a query hit message along the reverse path of the corresponding query message. An alternative design would be for Bob to establish a direct TCP connection with Alice and send the query hit message over this connection. What are the advantages and disadvantages of such an alternative design?
b. An alternative approach, which does not use message identifiers, is as follows. When a query message reaches a peer, before forwarding the message, the peer augments the query message with its IP address. Describe how peers can use this mechanism to accomplish reverse-path routing.
c. When the peer Alice generates a query message, it inserts a unique ID in the message's Message ID field. When the peer Bob has a match, it generates a query hit message using the same Message lD as the query message.Describe how peers can use the Message lD field and local routing tables to accomplish reverse path routing.
