Jan Kiszka wrote: > Karl Reichert wrote: > > Hi, > > > > have again a small question concerning rt data frames: > > Which EtherType do they have, if no upper protocol (like IP) is > following? I'm talking about the case, that just plain payload data is in > payload > part of ethernet frame (raw packet access). > > > > As I saw in rtnet/examples/xenomai/posix/raw-ethernet.c, EtherType is > 0x1234. Is this the 'offical' type for plain data in RTnet or is it just sth > I can choose on my own (with respect to collision with already given > EtherTypes, like 0x0800 for IP). > > You may choose 0x0815 or 0x4711 as well :), ie. the type is up to the > user minus those types that are otherwise present on the real-time > network segment (eg. RTmac, RTcfg, or IPv4/ARP). > > Jan > And how does the receiver knows which size my payload has? Every Ethernetframe consists at least of 64 Byte, so I send a payload of 5 Byte, he always gets 50 Bytes of Payload. I could use the EtherType field as a Length field, as made by Novell (IPX). But I think this isn't working, because how does the receiver app get's the data then - socket() wnats to know the protocol.
Conclusion: I have to define my EtherType (like 0x1234) and start my data with a length field. Right? Or any other way I don't see yet? Thanks in advance Karl -- von Karl Reichert Ist Ihr Browser Vista-kompatibel? Jetzt die neuesten Browser-Versionen downloaden: http://www.gmx.net/de/go/browser ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ RTnet-users mailing list RTnet-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/rtnet-users
