Re: What is 802.3ae WAN-PHY?
I don't see any showstoppers in your note with respect to Ethernet OAM&P
supporting all legacy OAM&P requirements. This is not to say that there isn't a
lot of work to be done.
Praveen Kumar wrote:
> >Question: while the 1:1 logical connection is easy for me to make, would
> >there be any issue regarding the amount of data that could be carried in the
> >SONET overhead compared to the amount of data that could be carried in the
> I think there is still quite some work to be done with respect to mapping
> the SONET (or OAM&P) overhead onto the IPG. For example, even if we decide
> to use the IPG to carry the overhead, it would still be useful to preserve
> the notions of section,line & path. How is this layered overhead going to be
> distributed. Also, it would still be useful to allow multiple 10G signals to
> be multiplexed to a higher rate signal downstream. SONET framing does all of
> this for us TODAY.
> Another issue associated with using IPG to carry overhead is that, the ratio
> of overhead to payload is now a function of payload (packet) size. This
> means that the bandwidth consumed by the overhead channel (IPG) is now
> unpredictable and Iam not sure if carriers are going to like this.
> Nevertheless, I see some benefits associated with the 10GENIE approach. I
> think the question of "Why SONET framing" has not been convincingly answered
> by the "WAN PHY" proposal. For example, SONET is not the only transport
> network. What if one needs to connect the 10G WAN link to an all-optical
> (non-SONET) wavelength switched transport network. Is the STS signal the
> most optimal in this scenario?
> >> -----Original Message-----
> >> From: Osamu ISHIDA [mailto:ishida@xxxxxxxxxxxxxxxxxxx]
> >> Sent: Tuesday, April 04, 2000 7:50 AM
> >> To: Gary Nicholl; stds-802-3-hssg@xxxxxxxx
> >> Subject: What is 802.3ae WAN-PHY?
> >> Dear Gary,
> >> Thank you for your intelligible feedback. Now I became convinced
> >> that I speak English :-). I am happy to hear the Japanese style
> >> here, Nicholl-san! But please feel free to say just Osamu, because
> >> it helps me to trust (fake?) myself that I speak English.
> >> http://grouper.ieee.org/groups/802/3/10G_study/email/msg01952.html
> >> Also, thanks to you, I became convinced that we have some issues of
> >> clock tolerance compensation in SONET-framing that Rich has pointed
> >> out farsightedly.
> >> http://grouper.ieee.org/groups/802/3/10G_study/email/msg01866.html
> >> On the other hand, it seems to me that this community has consensus
> >> that the ELTE, not the WAN-PHY with SONET framer, is the demarcation
> >> point between SONET and Ethernet. In other words, WAN-PHY with SONET
> >> framer or Uni-PHY with WIS (WAN interface sublayer) should not be
> >> SONET. (All, please let me know if this is a wrong observation.)
> >> http://grouper.ieee.org/groups/802/3/10G_study/email/msg01958.html
> >> http://grouper.ieee.org/groups/802/3/ae/public/mar00/frazier_1
> >> _0300.pdf
> >> Then why we need WAN-PHY or WIS other than ELTE?
> >> The answer is in Mr. Paul Bottorff's slides in Albuquerque; the
> >> router/SW requires minimal management capability of WAN.
> >> http://grouper.ieee.org/groups/802/3/ae/public/mar00/bottorff_
> >> 2_0300.pdf
> >> Here I completely agree with Paul. This is indispensable to meet the
> >> PAR scope "add parameters and mechanisms that enable deployment of
> >> Ethernet over the Wide Area Network".
> >> http://grouper.ieee.org/groups/802/3/ae/PAR-802-3ae.pdf
> >> Then do we need SONET-frame between WAN-PHY and ELTE?
> >> In my opinion, the answer is NO.
> >> Once we have Mr. Shimon Muller's open-loop control to provide
> >> OC-192c/VC-4-64c compatible MAC rate, my understanding of the need
> >> for the SONET-framed PHY or WIS is limited to the OAM&P capability
> >> supported by minimal overhead bytes in a SONET frame.
> >> http://grouper.ieee.org/groups/802/3/ae/public/mar00/muller_1_0300.pdf
> >> http://grouper.ieee.org/groups/802/3/ae/public/mar00/figueira_
> >> 1_0300.pdf
> >> Here you have another solution 10GENIE; Layer-1 signaling by using
> >> interpacket gap.
> >> http://grouper.ieee.org/groups/802/3/ae/public/mar00/ishida_1_0300.pdf
> >> Assuming that 10GENIE can support the similar OAM&P to the ELTE, my
> >> perspective says that 10GENIE would be cheaper than WAN-PHY and WIS;
> >> no SONET framer (pointer manipulation), much less extra buffer for
> >> OAM&P data insertion, no 9.95Gb/s CLK, no jitter-tolerance
> >> limitation.
> >> I will shed light on this comparison in my up-dated 10GENIE proposal
> >> in Ottawa.
> >> Of course I have understood that 10GENIE has a tough problem
> >> indicated
> >> by Mr. Steve Haddock; Who is going to define how to OAM&P?
> >> http://grouper.ieee.org/groups/802/3/10G_study/email/msg01919.html
> >> My perspective says that IEEE 802 is the only candidate to be able to
> >> define it. I know that this don't suit the traditional
> >> 802.3's taste,
> >> but still I hope to have your support to define it. Otherwise we
> >> will see the law of the jungle until some de facto OAM&P has
> >> established; we will see wasteful investment to every potential loser
> >> and local dialect cutting the market into pieces. We will fail to
> >> catch a golden opportunity to unify LAN/WAN hardware for datacom at
> >> 10 Gb/s; and may degrade huge unified market potential.
> >> In Ottawa, I will show you how 10GENIE OAM&P is simple and easy-
> >> interoperable. I will restrict it to non-negotiable functions.
> >> I think this may be simpler than the auto-negotiation with config-
> >> register defined in 802.3z Clause 37.
> >> All, any feedback on this matter would be greatly appreciated.
> >> Best Regards,
> >> Osamu
> >> At 4:08 PM -0400 00.4.3, Gary Nicholl wrote:
> >> > I agree with Ishida-san.
> >> >
> >> > I think we need to understand that there are two separate
> >> issues here.
> >> >
> >> > (1) clock tolerance/accuracy specifications (i.e.
> >> +/-100ppm, +/-4.6 ppm, etc)
> >> > (2) jitter budget specifications (jitter generation,
> >> transfer and tolerance)
> >> >
> >> > The first one determines the lock range of any oscillators
> >> and phase look loops in the network. In SONET the worst case
> >> clock accuracy/tolerance is specified as +/- 20ppm and
> >> therefore every oscillator and clock recovery circuit in a
> >> SONET network should be able to lock on and hold to a +/-
> >> 20ppm signal.
> >> >
> >> > The second one, as Ishida-san points out is, effectively
> >> determines the maximum number of through-timed regenerators
> >> that can be traversed on an end-end SONET link to maintain a
> >> specified link bit error rate.
> >> >
> >> > These two specifications (i.e. clock tolerance/accuracy and
> >> jitter) are completely intendant. However from my experience
> >> in dealing with POS (packet over SONET) there is a tendency
> >> among some people to assume that they are related, in that a
> >> more accurate clock (say 4.6ppm rather than 20ppm)
> >> necessarily has better jitter performance. This is not the
> >> case. In fact SONET has a single set of jitter specifications
> >> (generation, transfer and tolerance) that are the same
> >> irrespective of whether an interface is clocked from a
> >> stratum 1 clock, a stratum 3 clock (4.6ppm) or a 'SONET
> >> minimum' clock (20ppm).
> >> >
> >> > As a reference point POS interfaces use a 20ppm clock and
> >> are fully compliant with the SONET/SDH jitter specifications
> >> in Bellcore GR-253 and ITU G.958.
> >> >
> >> > Gary ........................
> >> -----------------------------------------
> >> Osamu ISHIDA
> >> NTT Network Innovation Laboratories
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