RE: [EFM] 1 Gbps != 999.9 Mbps
Bob,
All services, no matter what level have management issues that are best
handled by that level. For example, IP content services have application
to applications management messaging that goes over the IP infrastructure,
the IP infrastructure has RFC based management that goes over the data link
layer protocol, which in turn goes over a physical transmission
infrastructure. The physical infrastructure is managed at the physical
layer, out-of-band, and transparent to all of the upper layers. The
physical layer management is so transparent that many of the IP community
claims that it does not exist at all, yet see what happens when the
"circuit" that they have leased to get from one location to another has
problems. Even the IP content services are still dependant on the ability
of the service providers to do the "out-of-band" physical layer
troubleshooting to re-establish their IP service.
Thank you,
Roy Bynum
At 08:23 PM 9/28/01 +0100, Bob Barrett wrote:
>Barry
>
>Very good points.
>
>What I was trying to do by raising this issue was get a debate going, and I
>seem to have achieved that.
>
>We Brits are renown for compromise, and what EFM needs (imho) is a
>compromise from the carrier types on the rigid requirement that _all_ OAM
>must be side band, and a compromise from the LAN types that _none_ of the
>OAM functions need to be side band.
>
>Again - imho - some of the basic parameters need to be side band, however,
>most of the detailed config. parameters should be in-band and don't fall
>within the scope of EFM (most equipment is implemented like this already via
>SNMP, why re-invent the wheel ?).
>
>The un-invented wheel is carrier class PHY layer management for EFM, really
>basic stuff like monitoring the interface condition at the PHY layer within
>the CPE, specifically for optical p2p and p2mp EFM.
>
>Note - we don't need to compromise the quick to market and low cost
>'leverage the silicon' argument by taking both the in-band and the side-band
>approach in p2p, and that is my main focus. Side band might mean tweaks to
>the MAC PHY boundary in a few ASICs,
>
>.....but then I don't use ASICs :-).
>
>I agree that all the detailed isochronous circuit stuff is vendor specific
>or within ietf territory, definitely not 802.3.
>
>Thank you
>
>Bob Barrett
>
> > -----Original Message-----
> > From: owner-stds-802-3-efm@majordomo.ieee.org
> > [mailto:owner-stds-802-3-efm@majordomo.ieee.org]On Behalf Of O'Mahony,
> > Barry
> > Sent: 28 September 2001 01:23
> > To: 'stds-802-3-efm'
> > Subject: RE: [EFM] 1 Gbps != 999.9 Mbps
> >
> >
> >
> > Greetings,
> >
> > 999.9 Mbps is within 100 ppm of 1 Gbps. Does the delivered bit
> > rate need to
> > be more precise than that? Suppose the OAM overhead is lower, such as the
> > 10K mentioned below, is that still too much?
> >
> > It seems to me that, if the requirement is to provide customers with the
> > type of isochronous-type of service they can get from T1, DS[x],
> > or ATM-type
> > interfaces, with bit throughput guaranteed and drived from some precision
> > clock hierarchy, then perhaps Ethernet is not the best choice to meet this
> > requirement.
> >
> > Ethernet instead has tended to talk about "Classes" of networks that
> > reference the raw bitrate, but don't really guarantee precise throughput,
> > right?
> >
> > I would think that if a service was being sold as providing "1000BASE-x
> > performance", most customers would comprehend what that was like. And
> > certainly perceive it as a very attractive offering. Perhaps provisions
> > could be made in the EFM specs. to add isochronous-type
> > guarantees, but one
> > needs to ask whether doing so would compromise the simplicity and
> > flexibility that makes Ethernet so attractive for EFM in the first place.
> > I'm just worried about the dangers of "feature creep".
> >
> > ~~~~~~~~~~~~~~~~~~~~~~~~~~
> > Barry O'Mahony
> > Intel Architecture Labs
> > Hillsboro, OR, USA
> > tel: +1(503)264-8579
> > barry.omahony@xxxxxxxxx
> > barry.omahony@xxxxxxxxxxxx
> > ~~~~~~~~~~~~~~~~~~~~~~~~~~
> >
> > -----Original Message-----
> > From: Bob Barrett [mailto:bob.barrett@xxxxxxxxxxxxxxx]
> > Sent: Thursday, September 27, 2001 4:11 PM
> > To: Harry Hvostov; fmenard@xxxxxxxxxxxxxxx; 'Denton Gentry'
> > Cc: 'stds-802-3-efm'
> > Subject: RE: [EFM] 1 Gbps != 999.9 Mbps
> >
> >
> >
> > Harry et al
> >
> > yup, all the IP 'stuff' is payload as far as the demarcation point is
> > concerned.
> >
> > The demarc is a PHY that carries packets at the end of the day.
> > Some demarcs
> > may be buried inside a bigger system, however, the standard must
> > also cater
> > for stand alone demarc devices. My expectation as a user would be that at
> > the demarc the bandwidth was the same capacity as my enterprise
> > MAC and PHY
> > of the same spec.
> >
> > Would I miss 10k per second on a 1GE, I doubt it.
> >
> > Would my test gear pick it up on an end to end private circuit
> > test, I don't
> > know, anyone on the reflector tried this?
> >
> > Bob
> >
> > > -----Original Message-----
> > > From: Harry Hvostov [mailto:HHvostov@xxxxxxxxxxxx]
> > > Sent: 27 September 2001 17:41
> > > To: 'fmenard@xxxxxxxxxxxxxxx'; 'Denton Gentry';
> > > bob.barrett@xxxxxxxxxxxxxxx
> > > Cc: 'stds-802-3-efm'
> > > Subject: RE: [EFM] 1 Gbps != 999.9 Mbps
> > >
> > >
> > > And how about the ICMP and IGMP traffic from the same CPE devices?
> > >
> > > Harry
> > >
> > > -----Original Message-----
> > > From: Francois Menard [mailto:fmenard@xxxxxxxxxxxxxxx]
> > > Sent: Thursday, September 27, 2001 6:05 AM
> > > To: 'Denton Gentry'; bob.barrett@xxxxxxxxxxxxxxx
> > > Cc: 'stds-802-3-efm'
> > > Subject: RE: [EFM] 1 Gbps != 999.9 Mbps
> > >
> > >
> > >
> > > Or for that matter, what about ARP traffic unsolicited from my CPE
> > > devices ?
> > >
> > > -=Francois=-
> > >
> > > -----Original Message-----
> > > From: owner-stds-802-3-efm@majordomo.ieee.org
> > > [mailto:owner-stds-802-3-efm@majordomo.ieee.org] On Behalf Of Denton
> > > Gentry
> > > Sent: September 26, 2001 3:12 PM
> > > To: bob.barrett@xxxxxxxxxxxxxxx
> > > Cc: stds-802-3-efm
> > > Subject: [EFM] 1 Gbps != 999.9 Mbps
> > >
> > >
> > >
> > > > Service providers have a desire to offer a full 1GE service and not
> > > > use any of it's bandwidth for OAM. The rule of conservation of
> > > > bandwidth means the OAM needs to go somewhere other then in the
> > > > bandwidth reserved for the 1GE payload. I take it as read that 100%
> > > > utilisation of a 1GE is unlikely, but that is not the point. The point
> > >
> > > > is that service providers want to offer 1GE service period, not a
> > > > 999.9Mbit service.
> > >
> > > Does the existence of the Mac Control PAUSE frame therefore make
> > > Ethernet unsuitable for service providers?
> > >
> > > Denton Gentry
> > > Dominet Systems