RE: [EFM] Question regarding OAM in 802.3ah D1.3
> >
> > If there is a MAC layer in the ONU, then OAM terminates there. If a
> > vendor builds something without a MAC layer, then it
> doesn't terminate
> > there. If you put MACs in your ONU, you're really building
> something
> > akin to a 2-port bridge (likely with STP disabled
> > permanently). If you
> > don't, then its more along the lines of a media converter.
> > Both models
> > can work. Both models can interoperate.
>
> Actually they don't interoperate. In the following figure:
>
> ONU1 -------- OLT1/GFP------- GFP/OLT2 ------------ ONU2
> Ethernet SONET Ethernet
>
>
>
> Assume OLT1 not terminating OAM received from ONU1 and not
> generating any
> OAM toward ONU1, while OLT2 does terminate OAM received from
> ONU2 and generates
> OAM toward ONU2. Now if ONU1 sends an OAM request to ONU2,
> the response of that
> request will be terminated at OLT2 and will never reach ONU1.
>
> So both sides should implement the same method.
>
Although the horse is already dead, buried, and decomposing, I'll kick it one more time just for grins.
You say: "OLT2 does terminate OAM received from ONU2 and generates OAM toward ONU2". Maybe its me, but its a bogus example. If there is a MAC in OLT2 facing ONU2, then it terminates and receives. There aren't many protocols that work if both ends aren't running it.
My point was that
a) OLT1 could be a 2-port MAC device, implementing OAM in both directions.
b) OLT2 could be the infamous "media converter" which doesn't really exist but which we always talk about anyway, which does not officially have a MAC in either direction
So when I said the 2-port bridge and the media converter model interoperate, thats all I meant. If you make-up some other kind of device, then I'm not thinking about it.
- Matt