On Apr 21, 2014, at 3:24 PM, Philip Rosenberg-Watt <p.rosenberg-w...@cablelabs.com> wrote:
> On 4/21/14 15:58 , "Guy Harris" <g...@alum.mit.edu> wrote: > >> OK, so frames for LINKTYPE_ETHERNET_P2MP, or whatever we end up calling >> it, are: >> >> the last 6 octets of the modified preamble as specified by 65.1.3.2 >> "Transmit" in 802.3-2012 > > Correct. OK - is LINKTYPE_ETHERNET_P2MP a good name, or might there be other flavors of point-to-multipoint in the future, so that we should call this LINKTYPE_ETHERNET_P2MP_EPON or something such as that? >> >> followed by >> >> a regular Ethernet frame (with the destination MAC being the MAC of the >> splitter, rather than the MAC of the final destination?)? > > The destination MAC is the same as defined for Ethernet in IEEE 802.1. I > can't find anything in the specification that says that the ONU/OLT will > rewrite the destination MAC. The ONU/OLT has an internal mapping to > associate LLIDs with MACs of connected devices, and uses it for forwarding > packets to the appropriate Ethernet port. So why doesn't the destination MAC suffice to determine which is the appropriate Ethernet port? >> And those would be LINKTYPE_ETHERNET, with just a regular Ethernet frame >> with the right destination MAC, and nothing preceding the destination MAC? > > Yes, because the sniffer would be connected downstream of the ONU/OLT E.g., connected to the Ethernet in the subscriber's home? _______________________________________________ tcpdump-workers mailing list tcpdump-workers@lists.tcpdump.org https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers
