Consider the data center network with hierarchical topology in Figure 5.30. Suppose now there are 80 pairs of flows, with ten flows between the first and ninth rack, ten flows between the second and tenth rack, and so on. Further suppose that all links in the network are 10 Gbps, except for the links between hosts and TOR switches, which are 1 Gbps.
a. Each flow has the same data rate; determine the maximum rate of a flow.
b. For the same traffic pattern, determine the maximum rate of a flow for the highly interconnected topology in Figure 5.31.
c. Now suppose there is a similar traffic pattern, but involving 20 hosts on each hosts and 160 pairs of flows. Determine the maximum flow rates for the two topologies.
a)
Link capacity=10 Gbps
=10000 Mbps (Since, 1Gbps=1000Mbps)
Flow pairs count=80
Formula of the maximum rate of a flow to given data:
b)
Refer the Figure 5.31 in the textbook.
Each host contains number of paths from a tier-1 to tier-2 is 4. So, Path count=4
c)
Take 20 hosts on each hosts and 160 pairs of flows.
So, flow pair count=160 for first topology like the data center network with hierarchical topology in Figure 5.30.
next, flow pair count =20 for second topology like the highly interconnected topology in Figure 5.31.
First topology: Data center network using Hierarchical topology
Second topology: Highly interconnected network:
Here, flow pair count =20