On Mon, Dec 11, 2017 at 04:17:14PM +0100, Frantisek Rysanek wrote: > ...oops... ...forgot to post this to the mailing list...
and again, my reply was: On Mon, Dec 11, 2017 at 12:42:20PM +0100, Frantisek Rysanek wrote: > If I provide an UTC-synchronous PPS externally (from a GPS receiver), > to maybe 4 ports of i210, how do I reference that precise timestamp > to UTC "time of day" when analyzing a resulting PCAP file ? By the > time of last modification of the file? Or do the four separate PHC's > get synchronized to UTC somehow automagically? No, you must synchronize them. The program I posted shows how to synchronize them to each other. If you have a PPS available, then simply use that as an input to the four cards. You will have to adapt the program in that case. If you don't have a local PPS, but you do have a GM, then you can synchronize one card to the GM via PTP, and then synchronize the other cards to the first card, either using phc2sys (with best effort SW time stamping) or using the SDP signals (with HW time stamping). > The PCAP file normally seems to have an initial absolute timestamp in > the header, consequently Wireshark can show absolute UTC-referenced > timestamps per packet if asked to... Will it work like that with > adapter_unsynced ? Yes, I think so. But remember the HW time stamps will be TAI when using a GM. Wireshark will not know what the timescale actually was. If you interpret what you see on the screen from Wireshark as UTC, then you will be off by the number of leap seconds. > Is the HW timestamping support dependent on the internal metallic > PHY, or does it work with an external SGMII-based fiber PHY as well? On the i210, the time stamps are generated in the MAC (probably from the MII bus) and not in the PHY, and so I would expect fiber to work as well. You can always ask your Intel rep. just to be sure. HTH, Richard ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Linuxptp-devel mailing list Linuxptp-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
