In this example the network consists of one client, one router and one server.
IP addresses and routing tables are set up by using mrt files.

The client sends 100 MB of data to the server using TCP.

The dropsGenerator at client's PPP interface deletes certain DATA packets.
On server side a second dropsGenerator deletes certain ACK packets in configs 1-5.
For config 6 the node type of the server must be changed to
'StandardHostWithDLDuplicatesGenerator' in ned file to duplicate certain
received DATA packets.

Different configurations reflect examples from RFC 2018 and RFC 2883 to evaluate
the implementation of TCP's optional selective acknowledgment (SACK) option.
