tcpdump mailing list archives
Re: New LINKTYPE_ for EPON
From: Guy Harris <guy () alum mit edu>
Date: Mon, 21 Apr 2014 15:42:48 -0700
On Apr 21, 2014, at 3:24 PM, Philip Rosenberg-Watt <P.Rosenberg-Watt () cablelabs com> wrote:
On 4/21/14 15:58 , "Guy Harris" <guy () 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 802.3-2012Correct.
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
Current thread:
- New LINKTYPE_ for EPON Philip Rosenberg-Watt (Apr 18)
- Re: New LINKTYPE_ for EPON Guy Harris (Apr 18)
- <Possible follow-ups>
- Re: New LINKTYPE_ for EPON Guy Harris (Apr 21)
- Re: New LINKTYPE_ for EPON Guy Harris (Apr 21)
- Re: New LINKTYPE_ for EPON Guy Harris (Apr 22)
- Re: New LINKTYPE_ for EPON Guy Harris (Apr 22)
- Re: New LINKTYPE_ for EPON Guy Harris (Apr 23)
- Re: New LINKTYPE_ for EPON Michael Richardson (Apr 23)
- Re: New LINKTYPE_ for EPON Guy Harris (Apr 23)
- Re: New LINKTYPE_ for EPON Guy Harris (Apr 23)
- Re: New LINKTYPE_ for EPON Philip Rosenberg-Watt (Apr 24)
- Re: New LINKTYPE_ for EPON Guy Harris (Apr 24)
- Re: New LINKTYPE_ for EPON Guy Harris (Apr 24)
- Re: New LINKTYPE_ for EPON Philip Rosenberg-Watt (Apr 25)