Does labVIEW use standard ethernet?

[jlivermore]

When using labVIEW ethernet (TCP/IP) scripts, does the script conform to the IEEE 802.3 ethernet standard? Specifically, are the ethernet packets the standard size..is the data portion between 46 and 1500 bytes? I'm asking because I have TCP/IP vi's that send jumbo packets; the data portion is 9.6K bytes. Are these packets broken down by the VI to conform to the IEEE standard and sent as multiple packets or are they sent as jumbo packets? TIA.

jlivermore

[altenbach]

The TCP tools in LabVIEW are high-level and you have no control about packets and packet structures. Whatever data you wire will get send, and you don't need to care how the data payload is packaged or fragmented. That's the responsibilty of the OS and not of LabVIEW. If your network works properly, LabVIEW will be able to use it.

For example if you open a TCP connection in LabVIEW, several packets will get send to establish the threeway handshake and later the connection is broken down with another packet exchange. All this is automatic and transparent.

What do you mean by "jumbo packets"? If your network (switches, etc.) and network adapters have support for jumbo frames, this feature might get used, but that's out of the control of LabVIEW.

Message Edited by altenbach on 11-05-2008 05:30 PM

[Andrey_Dmitriev]

Hi, jlivermore,

You can analyse TCP packets at low level with ethereal software.

Also read this old topic about transfering data with TCP

Andrey.

[jlivermore]

Thanks, Alt. You enlightened me. The "jumbo" data packets are constructed prior to ethernet transmission. The TCP/IP capability provided by the OS parses the data into ethernet packets. These packets are reconstructed by the client into "jumbo" data files.

-jlivermore

[jlivermore]

Thanks, Andrey. If I need to examine TCP packets, I will use ethereal software. Based on Alt's response to my question, I think I was confused about large data packets being constructed prior to invoking ethernet. When sent by ethernet, a large data packet is parsed into smaller ethernet frames as required. The packet is re-assembled by the client.

-jlivermore