Assume the three layer communication model from the previous chapter (application, transport, and communications). Assume the network is capible of supporting 10mb/sec. Assume that the following:
| Layer | Control Information | PDU Size |
|---|---|---|
| Transport | 10 bytes | 100 bytes |
| Network | 5 bytes | 125 bytes |
So in this case, 90 bytes of 125 are used for the application,
or 72% of the data transmitted is application data. This means
that the maximum throughput we can achieve is 7.2 mb/sec.
[root@imladras bennett]# ping 10.1.1.100 PING 10.1.1.100 (10.1.1.100) from 10.1.1.103 : 56(84) bytes of data. Warning: time of day goes back, taking countermeasures. 64 bytes from 10.1.1.100: icmp_seq=0 ttl=255 time=1.845 msec 64 bytes from 10.1.1.100: icmp_seq=1 ttl=255 time=1.380 msec --- 10.1.1.100 ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max/mdev = 1.380/1.612/1.845/0.235 ms
[root@localhost sbin]# tcpdump ip -nn Kernel filter, protocol ALL, TURBO mode (575 frames), datagram packet socket tcpdump: listening on all devices 14:10:37.630169 eth0 > 10.1.1.103 > 10.1.1.100: icmp: echo request (DF) 14:10:37.630169 eth0 < 10.1.1.100 > 10.1.1.103: icmp: echo reply (DF) 14:10:38.630169 eth0 > 10.1.1.103 > 10.1.1.100: icmp: echo request (DF) 14:10:38.630169 eth0 < 10.1.1.100 > 10.1.1.103: icmp: echo reply (DF)