Re: [802.3ae] a bit concerned...
Roy,
Thanks for writing back and I'm looking forward to seeing you in
Portland next week. My replies to your responses are included below.
Roy Bynum wrote:
>
> Rich,
>
> In response to your e-mail on a item by item issue.
>
> 1. The WAN PHY PMDs are esentually done because of the similarity to the
> SONET OC192.
I agree with you 100%. This is the very reason that development of the
WAN PHY in P802.3ae is a redundant activity. 10GE mapping to legacy
SONET equipment requires only rate control to match a 10 Gbps MAC rate
to a slower OC-192 line rate and a simple means of mapping Ethernet
packets to an OC-192c SPE. The PHY might as well be a SONET PHY since a
third PHY which is neither Ethernet nor SONET is superfluous.
The point I was making in my original point (1) is that technical
feasibility of a 10G Serial PHY has precedence in SONET and, as you add,
Digital Wrapper. The problem with SONET is one of economic feasibility
in light of end-to-end Ethernet competition from the 10GE LAN PHY.
> 2. There is no way that a 10.3 Gb/s signaling can not be more demanding
> than 9.9 Gb/s signaling.
Au contrare. Specifically at issue is whether 10.3125 GBaud signaling in
support of the 10GE LAN PHY architecture for MAN/metro applications to
40 km is more demanding than 9.95328 GBaud signaling in support of WAN
applications well in excess of 40 km? I'd say that the latter is a more
demanding application than the former. The proof is in the
point-to-point topology nature of the 10GE LAN PHY, which eliminates
jitter transfer requirements, and the link distance limit, which
additionally reduces the jitter contribution of the channel to the total
link jitter budget. This is exactly why 10GE LAN PHY jitter specs need
not be as demanding as those of SONET OC-192 and the reason for my
associated TR comment against D3.1.
> 3. Do not inter-mix OTN and ASON. Do not lump me into the telephony heads
> that are trying to re-create a redundant overhead for SONET and SDH. I am
> not a supporter of OTN or the Digital Wrapper and never have been. I do
> not see the need for DW technology except for submarine cable systems. The
> existing SONET and SDH technologies are doing a good job now and do not
> need to be replaced. As for 10GbE LAN PHY is the strongest contender for
> 10G MAN/metro applications, it depends on whether it is implemented by an
> enterprise user or a service provider.
I apologize for my erroneous association of you with OTN and Digital
Wrapper. I'll make sure to not do this in the future.
Submarine cable systems are nothing but ultra-long-haul links. The
reason to deploy Digital Wrapper technology there is because it is
expensive to put a retimer in the middle of the Bermuda Triangle. The
same goes for putting up an extra shack for a retimer in the middle of
Utah. As data rates inevitably go up due to demand and available
technology, additional technology such as FEC makes more sense to deploy
at the link ends than shacks, power stations and Yellow Submarine trips
to the Bermuda Triangle. I believe that the same technology is ready for
prime time in the metro make low cost 40-80 km links a reality.
As far as contenders go, the 10GE LAN PHY, coming from Ethernet, and
supporting end-to-end Ethernet will support Ethernet pricing,
scalability, manageability, familiarity, interoperability, etc. All
enterprise users are already sold on Ethernet, this is a no-brainer.
Service providers and carriers are already looking at Ethernet at 1G. I
predict that they'll be doing much more than looking at 10G.
>3) I have no clue at to what you're alluding too when you say: "The
> >issue that I have seen is stability at the higher signaling rate of the
> >LAN PHY". I believe that you are a staunch supporter of Optical
> >Transport Network (e.g. OTN, G.709, ASON, etc.) including the associated
> >PHY and PMD signaling rates in the range of 10.7 to 12.5 GBaud. Please
> >correct me if I am misinformed and you do not support these OTN
> >activities. The 10.3125 GBaud signaling rate of the P802.3ae LAN PHY is
> >again a slam dunk relative to OTN signaling, especially in consideration
> >of the much shorter reach and point-to-point only topology applications
> >for the LAN PHY. Bottom line is that the 10 Gigabit Ethernet LAN PHY is
> >the latest, an likely strongest, contender for 10G MAN/metro
> >applications.
>
> Thank you,
> Roy Bynum
>
> At 12:45 PM 7/4/01 -0700, Rich Taborek wrote:
>
> >Roy,
> >
> >As a representative of both a PHY component and
> >PMD/transceiver/transponder vendor for both P802.3ae LAN and WAN PHYs
> >I'd like to offer the following in rebuttal to your assertions:
> >
> >1) The P802.3ae WAN PHY and its associated PMD, is, for all practical
> >purposes, identical to that of SONET OC-192c and SDH VC-4-64c. Since the
> >latter devices have been in the market for quite some time, and designed
> >for longer reach applications than those specified in P802.3ae
> >objectives, I believe that technical feasibility is proven. Economic
> >feasibility... well that's another issue. However, it is unrelated to
> >the issue at hand;
> >
> >2) P802.3ae PMD objectives stop at supporting link distances of: "At
> >least 40 km over SMF". These are "slam dunk" distances for most SONET
> >equipment. In fact, changing "At least 40 km" to "80 km" is still a slam
> >dunk for SONET. This says to me that existing SONET PHY and PMD specs,
> >including optical and jitter specs, should be adequate, and are probably
> >too demanding for all P802.3ae applications. It seems to me that
> >P802.3ae PHY and PMD specifications, being more demanding than those of
> >SONET are inconsistent with intended P802.3ae applications. This is true
> >for both LAN and WAN PHY types. I am submitting a TR comment against
> >D3.1 to resolve this issue.
> >
> >3) I have no clue at to what you're alluding too when you say: "The
> >issue that I have seen is stability at the higher signaling rate of the
> >LAN PHY". I believe that you are a staunch supporter of Optical
> >Transport Network (e.g. OTN, G.709, ASON, etc.) including the associated
> >PHY and PMD signaling rates in the range of 10.7 to 12.5 GBaud. Please
> >correct me if I am misinformed and you do not support these OTN
> >activities. The 10.3125 GBaud signaling rate of the P802.3ae LAN PHY is
> >again a slam dunk relative to OTN signaling, especially in consideration
> >of the much shorter reach and point-to-point only topology applications
> >for the LAN PHY. Bottom line is that the 10 Gigabit Ethernet LAN PHY is
> >the latest, an likely strongest, contender for 10G MAN/metro
> >applications.
> >
> >Best Regards,
> >Rich
> >
> >--
> >
> >Roy Bynum wrote:
> > >
> > > Brad,
> > >
> > > As a customer that gets information individually from the vendors,
> > > including transceiver vendors, I have concerns over the discrepancy with
> > > OEM vendors that are pushing to develop the LAN PHY early instead of the
> > > WAN PHY and the ability of the transceiver vendors ability to deliver the
> > > WAN PHY PMD earlier than the LAN PHY PMD. The issue that I have seen is
> > > stability at the higher signaling rate of the LAN PHY. I am saying this in
> > > general context, not commenting on any one or group of system, component,
> > > or PMD vendors.
> > >
> > > This could make for some discrepancies in the ability to do feasibility
> > > and/or inter-operability testing, perhaps even in September.
> > >
> > > Thank you,
> > > Roy Bynum
> > >
> > > At 03:37 PM 7/2/01 -0700, Booth, Bradley wrote:
> > >
> > > >Just so everyone in the Task Force is aware, we have had very low
> > > >volume of comments submitted so far. I do have some concern as we
> > > >contemplate moving forward to Sponsor ballot. My primary concern is
> > > >that of demonstrated 10GbE interoperability. Without some level of
> > > >interoperability work, we may not have a draft that has been
> > > >reviewed and debugged as extensively as it needs to be. The lack of
> > > >comments along with the lack of demonstrated product is of grave
> > > >concern to me.
> > > >
> > > >Thank you,
> > > >Brad
--
Best Regards,
Rich
---------------------------------------------------------
Richard Taborek Sr. Intel Corporation
XAUI Sherpa Intel Communications Group
3101 Jay Street, Suite 110 Optical Products Group
Santa Clara, CA 95054 Santa Clara Design Center
408-496-3423 JAY1-101
Cell: 408-832-3957 mailto:rich.taborek@xxxxxxxxx
Fax: 408-486-9783 http://www.intel.com