> On Wed, Sep 24, 2014 at 10:57:08AM +0900, YAMAMOTO Takashi wrote: >> > Testing experimenter OXM is tricky because I do not know of any in >> > widespread use. Two ONF proposals use experimenter OXMs: EXT-256 and >> > EXT-233. EXT-256 is not suitable to implement for testing because its use >> > of experimenter OXM is wrong and will be changed. EXT-233 is not suitable >> >> sorry for sidetracking, how EXT-256 is wrong and will be changed? >> i'm interested because i implemented the extension in Ryu. > > The original design for OXM had 32-bit standard OXMs and 64-bit > experimenter OXMs. Then, later on, somehow this design was forgotten, > and experimenter OXMs were re-envisioned as 72, 80, 88, or 96 bits > long, where the additional 8 to 32 bits provided additional > experimenter-defined field information. This is difficult to handle > because the length of the additional bits is experimenter-specific, so > that a switch or controller cannot figure out whether two fields are > even the same unless it knows how long the additional bits are for > some specific experimenter. It is also not explained in the standard > anywhere. I don't know where it came from, but it seems like a > mistake and will be rectified by reissuing a corrected EXT-256. It > should not be necessary to actually change the OpenFlow standard > otherwise, since the standard didn't actually say to do anything this > way.
thank you for explanation. i remember that it was a mystery what oxm_field should be for EXT-256. YAMAMOTO Takashi _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
