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+NETWORK THROUGHPUT TESTCASE
+
+QTIP uses IPerf3 as the main tool for testing the network throughput.
+There are two tests that are run through the QTIP framework. 
+
+Network Throughput for VMs
+Network Throughput for Compute Nodes
+
+For the throughout of the compute nodes we simply go into the systems-under-test 
+and install iperf3 on the nodes. One of the SUTs is used a server and the other as a 
+client. The client pushes traffic to the server for a duration specified by the user
+configuration file for iperf. These files can be found in the test_cases/{POD}/network/
+directory. The bandwidth is limited only by the physical link layer speed available to the server.
+The result file inlcudes the b/s bandwidth and the CPU usage for both the client and server.
+
+For the VMs we are running two topologies through the framework.
+
+1: VMs on the same compute nodes
+2: VMs on different compute nodes
+
+QTIP framework sets up a stack with a private network, security groups, routers and attaches the VMs to this network. Iperf3 is installed
+on the VMs and one is assigned the role of client while other serves as a server. Traffic is pushed
+over the QTIP private network between the VMs. A closer look in needed to see how the traffic actually
+flows between the VMs in this configuration to understand what is happening to the packet as traverses
+the openstack network.
+
+The packet originates from VM1 and its sent to the linux bridge via a tap interface where the security groups
+are written. Afterwards the packet is forwarded to the Integration bridge via a patch port. Since VM2 is also connected
+to the Integration bridge in a similar manner as VM1 so the packet gets forwarded to the linux bridge connecting
+VM2. After the linux bridge the packet is sent to VM2 and is recieved by the Iperf3 server. Since no physical link is
+involved in this topology, only the OVS (Integration bridge) is being benchmarked and we are seeing bandwidth in the range
+of 14-15 Gbps.
+
+For the topology where the VMs are spawned on different compute nodes, the path the packet takes becomes more cumbersome.
+The packet leaves a VM and makes its way to the Integration Bridge as in the first topology however the integration bridge 
+forwards the packet to the physical link through the ethernet bridge. The packet then gets a VLAN/Tunnel depending on the network
+and is forwarded to the particular Compute node where the second VM is spwaned. The packets enter the compute node through the physical
+ethernet port and makes its way to the VM through the integration bridge and linux bridge. As seen here the path is much more involved
+even when discussed without the mention of overheads faced at all the internfaces so we are seeing the results in the range of 2 Gbps.
+
+
+ 
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