I'm new with SDN and I want to write Python code to create switch and three hosts and controller also send hello packet from the switch to the controller
You can use Mininet to create switches and use Pox as a controller.
Once you create a network topology in Mininet, you can run POX connecting switches in Mininet and switches will send Hello message to Pox automatically.
Here is the Mininet website: http://mininet.org
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when I generate iperf UDP traffic on a linear topology with 6 switches in mininet which is connected to RYU controller, I am getting a lot of packet in messages. like same switch is sending packet in messages for that traffic more than one time. Why is this happening? and how to solve this problem?
I am trying to get a notification (over REST connection) when any host is trying to communicate in my network. I registered for a Packet-in-message change-event-notification that I found in the packet-processing module. when I start listening using my websocket client, I receive nothing!!!!!
I was expecting some notification with each packet-in reaching the controller. am I miss-understanding the use of this module? what is the purpose of this packet-in-message?
Is there a way to get a notification when any host is trying to set a communication with another host (over REST)?
I built my topology in mininet. It contains some openflow switches and hosts. The Opendaylight controller has l2switching, restconf, openflowplugin and dlux features enabled.
I am developing simple loopback using gadgetfs, but I am a bit
confused as to how gadgefs knows that host initiated IN transfer.
Gadgetfs use read/write on endpoints, so as to my understanding, it can only:
When using "read" on OUT endpoint file descriptor - accept a new transfer from host
to device.
When using "write" on IN endpoint file descriptor - start transfer from device to host .
(1) above seems to be simple to understand, but I have
misunderstanding about (2):
Isn't it that a write into IN endpoint should be accepted only when
host initiated a transaction (according to usb standard) ?
If so, than how does gadget knows that host initiated a
transaction in the IN endpoint, and expects a transfer at this moment ?
Gadget will have a USB device controller which handles all the requests from the USB host controller. So the job of the GadgetFS is to fill the Endpoint buffers with the help of device controller driver. Following is the sequence of events -
Application running in USB gadget has some data to transfer to host
Application uses GadgetFS interface to transfer the data
GadgetFS then uses standard USB device controller driver API to send the data to the controller
USB device controller driver take the buffer address passed down by gadgetFS and add it in Asynchronous list of the targeted controller
Endpoint(EHCI controller)
When device controller received "IN" token request from the controller, your device controller will read the EP details from the
token and schedule the corresponding EP for data transfer.
Controller DMA then reads the data from the address of the buffer which was added in step 4
This is the overall steps. You can check the controller spec for more details.
These steps are more or less same for EHCI and XHCI.
Remember that all the transactions are taken care of by the device controller and the application/GadgetFS has a job to fill up the buffers pointed by EP.
I'm almost completely done with and iOS client for my REST service. The only thing I'm missing is the ability for the client to listen on the network for a UDP broadcast that receives the host display name and base URL for uploads. There could be multiple servers on the network broadcasting and waiting for uploads.
Asynchronous is preferred. The servers will be displayed to the user as the device discovers them and I want the user to be able to select a server at any point in time.
The broadcaster is sending to 255.255.255.255 and does not expect any data back.
I am a beginner in objective c so something simple and easy to use is best.
I recommend looking at CocoaAsyncSocket. It can handle UDP sockets well. I haven't tried listening to a broadcast with it, but it's probably your best bet.
I want to make a tool that monitors a couple of tcp and udp ports which will then be visualized in different views in an eclipse rcp application.
How should one go about doing this?
I have some trouble figuring out how to attach the TCP and UDP servers to the eclipse framework so that multiple views can listen on them and handle the information accordingly.
Each view can register itself as a listener to your network monitor using one of these methods:
Accessing directly network monitor singleton instance (like you've done):
NetworkMonitor.getInstance().addMonitorListener(this)
Make an OSGI service from your network monitor, then access it from your view using:
nmServiceTracker = new ServiceTracker(bundleContext, NetworkMonitor.class.getName(), null);
nmServiceTracker.open();
((NetworkMonitor) debugTracker.getServiceReference()).addMonitorListener(this)
See simple OSGI service tutorial for more info.
Create extension point for "Network Monitor Listeners". For more on creating extension points, refer to this great article.