Re: [EFM] Question regarding OAM in 802.3ah D1.3
Shahram,
It would be helpful to this discussion if you indicate what you had in mind
with regard to OAM frames so one can think of a pragmatic answer. For example
if you are worried about Pause frames: In this case the SONET/SDH (OLT1-OLT2)
is often the bottleneck link. So Pause is used on the local link to protect the
OLT-1/2 buffers. If the egress ONU back pressures the network, then OLT can
simply buffer and subsequently drop packets. Otherwise fairly large buffers
would be required to absorb the round trip time of the wide area. If you think
about it as a two port bridge, again Pause is not propagated over the wide
area. If you look at various IETF Pseudowire flavors, again following the lead
of IEEE, Pause is not propagated over the wide area.
Siamack
Geoff Thompson wrote:
> Matt-
>
> To further enrich the information that you provided below....
>
> 802.3 has a long, well established tradition of not supporting media
> converters.
>
> It would be my opinion that any "features" designed to specifically support
> media converters were out of scope unless they were specifically mentioned
> in the PAR.
>
> Geoff
>
> At 01:05 AM 2/12/2003 -0500, Matt Squire wrote:
>
> >My 2 cents.
> >
> >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. So do it anyway you want, and
> >maybe the market will agree with you.
> >
> >- Matt
> >
> >Shahram Davari wrote:
> > >
> > > Roy,
> > >
> > > Since EOS is a private line service, It seems that you agree with me
> > and Chak that for the EOS it seems from architectural point of view the
> > OAM MAC frames should not be terminated at OLTs. Is that correct?
> > >
> > > Yours,
> > > -Shahram
> > >
> > > > -----Original Message-----
> > > > From: Roy Bynum [mailto:rabynum@xxxxxxxxxxxxxx]
> > > > Sent: Tuesday, February 11, 2003 12:26 PM
> > > > To: Chau, Chak; stds-802-3-efm@ieee.org
> > > > Subject: RE: [EFM] Question regarding OAM in 802.3ah D1.3
> > > >
> > > >
> > > >
> > > > Chak,
> > > >
> > > > Depending on the service definition and who owns the service
> > > > facilities,
> > > > end to end OAM functionality would not necessarily available. In all
> > > > packet services, the service provider would own at least a
> > > > portion, if not
> > > > all of the communications facilities. The OAM functionality
> > > > would then be
> > > > for the use of the service provider, not the customer. Only
> > > > with a Leased
> > > > Circuit type of service (also referred to as "Private Line")
> > > > would end to
> > > > end, OLT1 to OLT2 OAM functionality exist. For all other types of
> > > > services, the OAM for Link 1 would not be the OAM for Link 2.
> > > > Other than
> > > > with a Leased Circuit service, the services are defined to
> > > > alter, filter,
> > > > or drop customer originated frames/packets in one way or
> > > > another, including
> > > > the OAM frames. This is the gist of the work that is being done by
> > > > SG15/Q.10 under E.Ethna. Other than with a Leased Circuit
> > > > service, true
> > > > "transparency" does not exist.
> > > >
> > > > Thank you,
> > > > Roy Bynum
> > > >
> > > > At 10:15 AM 2/11/2003 -0600, Chau, Chak wrote:
> > > > >Hi David and All,
> > > > >
> > > > >I though for a PtP application the OAMPDUs message should be
> > > > transparent
> > > > >form OLT1 to OLT2.
> > > > >Or else, this will defeat the purpose of PtP, i.e., no L2 frame
> > > > >processing. Which means that OAM for Link1 can be OAM for
> > > > Link2, is that
> > > > >correct? This topic may be reviewed outside of EFM if prefered.
> > > > >
> > > > >Kind Regards,
> > > > >Chak
> > > > >
> > > > >Chak Chau
> > > > >FUJITSU, Transmission Development
> > > > >Phone: (972) 479-2795
> > > > >chak.chau@xxxxxxxxxxxxxxx
> > > > >chakavuth.chau@xxxxxxxxxxxx
> > > > >-----Original Message-----
> > > > >From: David Martin [mailto:dwmartin@xxxxxxxxxxxxxxxxxx]
> > > > >Sent: Monday, February 10, 2003 2:59 PM
> > > > >To: stds-802-3-efm@ieee.org
> > > > >Subject: RE: [EFM] Question regarding OAM in 802.3ah D1.3
> > > > >
> > > > >Shahram,
> > > > >
> > > > >
> > > > >Agreed, the EoS (e.g. GFP-F) mapping is a simple
> > > > port-to-port mapping and
> > > > >doesn't include the full MAC sublayer processing (i.e. only
> > > > terminates
> > > > >IPG, preamble, SFD). Inspecting the MAC DA and filtering off
> > > > EFM OAMPDUs
> > > > >and processing them is required by the network application,
> > > > since the
> > > > >Ethernet link / PHY to which they apply is terminated. OAM
> > > > for link 1
> > > > >cannot be mixed with OAM for link 2 on the other side of the
> > > > provider's
> > > > >network.
> > > > >
> > > > >
> > > > >ONU1 -------------- OLT1/GFP------------------ GFP/OLT2
> > > > ------------ ONU2
> > > > > Ethernet SONET
> > > > Ethernet
> > > > >
> > > > >
> > > > >It might be more appropriate to continue this privately, or
> > > > on the Q.12/15
> > > > >reflector.
> > > > >
> > > > >
> > > > >...Dave
> > > > >David W. Martin
> > > > >Nortel Networks
> > > > ><mailto:dwmartin@xxxxxxxx>dwmartin@xxxxxxxx
> > > > >+1 613 765-2901 (esn 395)
> > > > >~~~~~~~~~~~~~~~~~~~~
> > > > >-----Original Message-----
> > > > >From: Shahram Davari [mailto:Shahram_Davari@xxxxxxxxxxxxxx]
> > > > >Sent: Monday, February 10, 2003 3:16 PM
> > > > >To: Martin, David [SKY:QW10:EXCH]; stds-802-3-efm@ieee.org
> > > > >Subject: RE: [EFM] Question regarding OAM in 802.3ah D1.3
> > > > >
> > > > >
> > > > >David,
> > > > >
> > > > >
> > > > >I like to agree with you, but from layering architectural
> > > > point of view,
> > > > >the EOS box does not have to implement MAC
> > > > >layer (i.e., do any MAC lookup), rather a P-2-P EOS is a
> > > > kind of port
> > > > >transport in which all traffic coming form an Ethernet port
> > > > are send over
> > > > >a specific SONET channel.
> > > > >
> > > > >
> > > > >Please see further comments in-line:
> > > > >
> > > > >
> > > > >Thanks,
> > > > >-Shahram
> > > > >-----Original Message-----
> > > > >From: David Martin [mailto:dwmartin@xxxxxxxxxxxxxxxxxx]
> > > > >Sent: Monday, February 10, 2003 3:00 PM
> > > > >To: stds-802-3-efm@ieee.org
> > > > >Subject: RE: [EFM] Question regarding OAM in 802.3ah D1.3
> > > > >Shahram,
> > > > >
> > > > >
> > > > >This question is somewhat out of scope wrt EFM, but the
> > > > answer is yes, the
> > > > >EFM OAMPDU flow must be terminated at the Provider Edge.
> > > > Otherwise it
> > > > >would flow through the provider's SONET network and get
> > > > mixed in with a
> > > > >separate EFM OAMPDU flow at the far end.
> > > > >
> > > > >
> > > > >SD=> Which separate OAMPDU flow? do you mean from ONU2 to OLT2?
> > > > >
> > > > >
> > > > > Note that you have the terms ONU / OLT reversed.
> > > > >
> > > > >
> > > > >So the ONU is the customer side?
> > > > >
> > > > >
> > > > >This "filter function" is being defined in the ITU-T SG15 /
> > > > Q.12 work in
> > > > >draft G.ethna (was G.etna) and in the OIF UNI v2.
> > > > >
> > > > >
> > > > >Thanks I will have a look.
> > > > >
> > > > >
> > > > >The PE-PE, or SONET portion is not an EFM link, but rather a
> > > > SONET path,
> > > > >which has its own OAM (i.e. POH).
> > > > >
> > > > >
> > > > >Agree.
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >...Dave
> > > > >David W. Martin
> > > > >Nortel Networks
> > > > ><mailto:dwmartin@xxxxxxxx>dwmartin@xxxxxxxx
> > > > >+1 613 765-2901 (esn 395)
> > > > >~~~~~~~~~~~~~~~~~~~~
> > > > >-----Original Message-----
> > > > >From: Shahram Davari [mailto:Shahram_Davari@xxxxxxxxxxxxxx]
> > > > >Sent: Monday, February 10, 2003 2:13 PM
> > > > >To: stds-802-3-efm@ieee.org
> > > > >Subject: [EFM] Question regarding OAM in 802.3ah D1.3
> > > > >
> > > > >
> > > > >Hi,
> > > > >
> > > > >
> > > > >802.3ah section 57 says that the OAM defined is for single link (or
> > > > >emulated link), and should not be forwarded by bridges/switches.
> > > > >
> > > > >
> > > > >My question is, in case of Ethernet over SONET transport
> > > > (GFP + Virtual
> > > > >concatenation), should the OAMPDU be terminated at the EOS
> > > > device or it
> > > > >should be transparently transported?
> > > > >
> > > > >
> > > > >Consider this example:
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >OLT1 -------------- ONU 1------------------ ONU 2 ------------ OLT 2
> > > > > Ethernet SONET Ethernet
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >Assume OLT1 and OLT2 are the customer equipments and ONU1
> > > > and ONU2 are
> > > > >provider
> > > > >transport equipments that transport Ethernet over SONET (but
> > > > don't do any
> > > > >switching/bridging).
> > > > >
> > > > >
> > > > >In this case should ONU1 terminate OAMPDUs from OLT1 or it
> > > > should sent
> > > > >them transparently to OLT2?
> > > > >In other words is OLT1--ONU1 considered a single link? what
> > > > about ONU1 to
> > > > >ONU2, is this also a link?
> > > > >
> > > > >
> > > > >Thanks in advance,
> > > > >Shahram Davari
> > > > >Senior Product Research Engineer
> > > > >R&D Research Ottawa
> > > > >PMC-Sierra, Inc.
> > > > >Phone: (613) 271-4018
> > > > >Fax: (613) 271-6468
> > > > >
> > > >
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