[[PageOutline]]

== Path Controller ==

As an example experiment, we have set up a [http://geminiportal.uky.emulab.net/path_controller Path Controller] tool. Click on the link or goto http://geminiportal.uky.emulab.net/path_controller . Accept the self-signed certificate.

=== Logging On ===
Log on using the information on your handout.

[[Image(path_controller_logon.png, 300)]]


The tool consist of a web interface that connects to the slice's nodes and allows you to change the routing paths and generate traffic between selected nodes. The interface has desktop-like windows that can be moved around and resized as you please. 

[[Image(path_controller_init_view.png, 300)]]

=== Topology Window ===
The first window we will examine contains the slice's topology.

[[Image(topo_init_view.png, 200)]]

Each circle represents a node in the network. The lines represent links. Note that the global node (GN) does not have links, it acts in the background. Left click and drag a node to rearrange them. For this tutorial arrange them so they match the geminiportal layout like so:

[[Image(topo_rearranged_view.png, 200)]] [[Image(gemini_portal_map.png, 350)]]

As you rearrange the nodes, note the window directly below the topology window. This is the information (Info) window.

=== Info Window ===
[[Image(info_window.png, 300)]]

This window has some brief information about the node or link that the cursor is currently over. This case has information about '''VM-1'''. The icon represents a virtual machine. The hostname is pcvm63-2.uky.emulab.net.

[[Image(info_window_vm1.png, 200)]]

This next case is for '''lan1'''. The icon represents a link. The ids are displayed for the two end points, along with each interface's ip address.

[[Image(info_window_lan1.png, 200)]]

== Create Traffic ==

=== Traffic Generator ===
The window with the [[Image(add_generator_button.png)]] button is the Traffic Generator.
Click the button to add a Traffic Generator.

[[Image(new_generator.png, 200)]]

The Traffic Generator has a traffic source (Src) node and destination (Dst) node, both of which must be set. The File Size defaults to 500MB and can be anything from 1 to 1000MB. To set the Src or Dst, left click on the desired node. Once the node is highlighted, click on the [[Image(set_src_button.png)]] or [[Image(set_dst_button.png)]] to set your choice.
Set the traffic from Src '''VM-1''' to Dst '''VM-4.

[[Image(set_vm1_src_arrows.png, 300)]] [[Image(traffic_choices_arrows.png, 300)]]

Start the traffic by clicking the [[Image(transfer_button.png)]] button. The button color will pulse and the text will change to Transferring while the transfer is in progress.

== View Default Traffic (lan1) on Gemini Portal ==
Switch to Gemini Portal tab in the browser.
Left click on the link line that connects '''VM-1''' to '''VM-4'''. This brings up the Graph Control for '''lan1'''. Check the checkbox for '''linkoctets'''.

[[Image(lan1_graphs_traffic_control_node.png, 400)]]

The interface traffic graphs for both ends of the '''lan1'' will be added to the left side of the page. Mouseover the graph to enlarge for a better view.
Since we started a transfer using the Traffic Generator, we see a burst of traffic on these graphs. The green bars represent incoming traffic. The blue lines represent outgoing traffic.

=== Add Custom Route (lan3, lan5, lan4) ===
=== Switch to Path Controller ===
The Traffic Path window allows you to add custom routes to the slice.

[[Image(path_window.png, 200)]]

The [[Image(add_path_button.png)]] button adds a new path based on the links that are selected in the topology window. The [[Image(reset_all_paths_button.png)]] button will reset the slice back to its default routes.


As we saw earlier, the default route between '''VM-1''' and '''VM-4''' follows the direct route via '''lan1'''. Now we will alter that route.
Set the path from '''VM-1''' to '''VM-4''' to follow links '''lan3''', '''lan5''', '''lan4'''.  Do this by left clicking on the links while holding the shift key. Once the three links are selected, click the [[Image(add_path_button.png)]] button. The results should look like this:

[[Image(path_354.png, 300)]]


Start traffic between '''VM-1''' and '''VM-4''' by pressing the [[Image(transfer_button.png)]] button.

*set path to 3 5 4

=== Switch to Gemini Portal ===
*see traffic on lan4

=== Switch to Path Controller ===
Set the File size to 1000MB. Start traffic by pressing the [[Image(transfer_button.png)]].

Now add another path (in addition to the existing path) between '''VM-1''' and '''VM-4''' that follows links '''lan3''' and '''lan0'''.

[[Image(path_30.png, 300)]]


*set path to 3 0 
=== Switch to Gemini Portal ===

*see traffic start on lan4 then switch over to lan0
*see traffic on lan0

=== Switch to Path Controller ===
Click the [[Image(remove_path_button.png)]] by each path to remove them. Or, click the [[Image(reset_all_paths_button.png)]] to remove all the paths in one step.

Start traffic again? 
=== Switch to Gemini Portal ===
See traffic on lan1 again?