[network] [Xie Xiren seventh edition] [the problem of calculation of throughput] a school of Etherne-CodePudding

In figure 3 to 30, A school of Ethernet switches have three interfaces and three departments respectively connected to the Ethernet, the other three interfaces and email servers, web servers, and connected to A router connected to the Internet, the figure of A, B and C are 100 MBPS Ethernet switches, assuming all the rate at which the link is 100 mbit/s, and in the figure 9 host any of can and any - A server or host communications,

1. Try to calculate the 9 host and a maximum of two server to produce the total throughput, why?

2. Assume that in figure 3 to 30 in all the speed of the link is still 100 Mbit/s, but in the three series Ethernet switches are to be 100 MBPS hub, try to calculate the 9 host and a maximum of two server to produce the total throughput, why?

 
Is the interpretation of the book to "here's nine host and both servers work, it's the total throughput of 900 + 200=1100 mbit/s, three departments have a host visit two servers and the Internet through a router, other host within the department of communication" 

Respectively assume ABC three department subordinate host Numbers for a1, a2, a3, b1, b2, b3, c1, c2 and c3 
Here is "the total throughput" refers to the server and the host to the data, but not with the server host receives data (such as Internet data sent to the c1 (Internet - & gt; C1))? Below is my calculation process: 

9 host and two servers=total throughput (the world wide web server - & gt; A1 + a1 - & gt; The world wide web server) + (b1 - & gt; The E-mail server + email server - & gt; B1) + (c1 - & gt; The Internet) + (a2 - & gt; A3 + a3 - & gt; A2) + (b2 - & gt; B3 + b3 - & gt; B2) + (c2 - & gt; C3 + c3 - & gt; C2)=(100 + 100) + (100 + 100) + (100) + (100 + 100) + (100 + 100) + (100 + 100)=1100 

If according to this calculation, however, that the second question is a problem, switches into a hub, can only use half duplex according to my algorithm becomes: 
The world wide web server - & gt; Under A certain host + email server - & gt; A specific host under the B + C under a master - & gt; Internet=100 + 100 + 100=300 
And for the interpretation of is?" Here each department is a collision domain, the maximum throughput of 100 Mbit/s, is the total throughput of 300 + 200=500 Mbit/s, "

I'm going to be completely this stupid, don't know how to calculate, the throughput,