I was thinking about this issue and it's more complex than it seems.
I just reviewed some parts of the network module and found out that the BW UtilizationModel (BW UM) is not used for anything.
We create a Host with a defined BW capacity. This capacity is used when placing or migrating VMs.
The Cloudlet's BW UM attribute should define the amount of BW the Cloudlet is expected to use along the time.
Different from local resources such as CPU or RAM, in order to really use BW, we would need to send packets
through the network. The way the BW UM is being used is as if BW was a local resource (such as RAM or CPU).
So, I don't think network simulations using this Cloudlet attribute will really have any valid results.
They are not sending packets to simulate network traffic, delay and possibly congestion.
Despite the VM BW is supposed to be used for limiting the amount of BW a VM can use,
that value is just being used when placing VMs.
After the placement, if you are using the network module (NetworkHost, NetworkVm, NetworkCloudlet),
the VM BW is not considered for anything else.
If a VM try to send packets that require more BW than the VM is allowed to use, it will use
(as long as the Host has available BW).
The Cloudlet BW UM would be used to limit the amount of BW a Cloudlet is allowed to consume
along the time. But if you are going to limit that, it would be a static value, in the same
way as the VM BW or Host BW. However, the values returned by a UM may be dynamic.
Therefore, currently, the Cloudlet BW UM doesn't make sense.
If you are using the NetworkHost that is connected to an EdgeSwitch, the Host BW is the
bandwidth of that Switch. This way, the Host BW attribute is not used to define
the delay to transfer packets, but the EdgeSwitch BW.
Having these two different ways to get a BW for a Host is quite confusing.
This network module in CloudSim is totally buggy. I've been fixing lots of issues, namely:
5, 13, 19, 45, 49, 57, 126
(especially related to your scenario), 132, 137, 138.
But this is a more complex issue that may require structural changes.
Manoel Campos da Silva Filho Software Engineer
Computer Science and Engineering Ph.D. Student at University of Beira Interior (Portugal)
Professor at Federal Institute of Education, Science and Technology of Tocantins (Brazil)