Jumbo frame support PXIe-8135RT

[xl600]

Does the PXIe-8135RT (LabView 2013 RT) support jumbo frames on its Ethernet ports?  If not, can it be configured to?

[BauerPower]

What is your application? Is it image acquisition with a GigE camera? If you are performing image acquisition, the IMAQdx driver will automatically enable jumbo frames when you are acquiring from a GigE camera but there isn't a way to manually set this if you aren't using IMAQdx.

[xl600]

No, this interface is a private Ethernet used only for high speed simulation data.  The application needs to extract data from this simulation network, time tag it, and store it next to analog and video data collected from other interfaces (Analog, discrete, accelerometers, and high speed CameraLink cameras someing in from FlexRIO + NI1483 boards.  The Jombo frame support is needed for the sim data only.

I need to capture the frames, decode them, filter, tag, then store onto the local disk. It does seem that if IMAQdx can do this then there should be a way for me to do it as well.  It's obviously not an OS limitation in PharLap.

Robert

[BauerPower]

What type of throughput are you looking to acheive? It makes sense to me that there is likely a DLL call into the ethernet driver on the Pharlap system (just like enabling jumbo frames on windows), so perhaps it is possible with the System Exec VI running a terminal command or a Call Library Function node. This isn't something that's supported but I'll do some digging and see if I come up with a viable method.

[xl600]

The frames on this sim network consist of all UDP broadcast (Plus some low rate TCP/IP).  The UDP broadcast frames are a mix of small packets (Timing, frame start/stop, etc) combined with multiple packets per frame of mixed data (By mixed, I mean a very small fraction are jumbo, most are not).

My task is to be able to receive all UDP broadcast packets, filter out ones I don't care about (By reading the first few bytes of the packet data) and to fully process ones I do care about.  Of all the UDP broadcast packets transmitted, I only need to fully process maybe 4 small packets and a a few data packets per frame.

Frames run at up to 200 Hz.

To keep up, the packet filtering process will have to be very rapid since packet decoding and encoding of the packets I'm interested in will take the majority of the time to deal with (I'll be passing those through RT FIFOs to data processing and storage VIs).

I'd guess a few hundred mbps hitting the port.

[BauerPower]

While there isn't an easy way to enable jumbo frames on the RT PXI controllers, I think that for your application you'll be able to reach your desired throughput without enabling jumbo frames. I've attached a white paper that has some benchmarking for simple TCP communication in LabVIEW on an RT PXI-8106 controller. This benchmarking shows that for large data sizes, you should be able to achieve >360Mbit/s. 

If you absolutely require changing the MTU of you ethernet interface, you may be able to do so through a network driver DLL call, however that's not something that we support and could result in having to format your PXI controller and start from scratch.

http://www.ni.com/white-paper/12267/en/

[xl600]

I have no control over the presense of jumbo frames in the received UDP packets.  The switches are configured for JF's and all sim hosts on the network are configured to receive JFs at layer 2.  If I can't get JFs enabled on the RT PXI controller, that means I cannot receive those frames (They'll get dropped because of the MTU mismatch at the PXI controll Ethernet interface).  I don't know if that will be a show stopper yet (I may be able to work around it, but it would require some effort in figuring out other ways to get the lost data into the PXI controller).

[BlueCheese]

The network stack and drivers on PharLap do not currently support jumbo frames for general UDP/TCP traffic besides for GigE Vision.

[xl600]

So the stack and drivers were written specifically for GigE Vision?  Or is it that GigEVision is the only portion of the LabView RT OS that takes advantage of jumbo frames?

[BauerPower]

GigE vision installs a different network stack on the target. It is possible (but untested) that installing the GigE Vision Driver on your PXI target would enable jumbo frames for normal network traffic. This isn't something that we currently support but if you want to try it, you could just install the GigE vision driver, sent your PXI target a jumbo packet, and see if you receive the packet properly with a LabVIEW TCP read.