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Re: [EFM] RE: Pause frame usage in transport networks


From 31.3: "Frames destined for the MAC Control sublayer (MAC
Control frames) are distinguished from frames destined for MAC
Control clients by a unique Length/Type field identifier."

If OLT1 is indeed a true MAC with a bridging layer above it
then it will see this as a MAC Control frame. If the DA doesn't
match the multicast address or OLT1's SA, then OLT1 may discard
the frame but it will not pass it up to the bridge.


Shahram Davari wrote:
> Hi all,
> Based on 802.3 standard, the PAUSE frames may have an individual or multicast MAC address (including broadcast).
> It seems to me if the ONU1 sends PAUSE frames with Dest MAC address of ONU2, then the OLT1 would
> relay that to ONU2 (no matter if OLT1 behaves as a transparent box or as a bridge), while if the ONU1
> sends a PAUSE frame with Dest MAC address of OLT1 or a multicast MAC address then the PAUSE frames
> would be terminated at OLT1 if OLT1 behaves like a bridge.
> ONU1---------OLT1/GFP-------GFP/OLT2------ONU2
>       Eth              EOS            Eth
> In other words for end-to-end OAM, if we know that OLT1 does not terminate any OAM frames, then ONU1 may use either
> Dest MAC address of ONU2 or a multicast address, but if we know that OLT1 terminates MAC, then ONU1 should use Dest MAC address of ONU2. To be is safe side it seems that for end-to-end OAM, it is best if ONU1 always sets the Dest MAC address to that of ONU2.
> Correct?
> Yours,
> -Shahram

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