Re: What is 802.3ae WAN-PHY?
Osamu,
Are you making the assumption that ELTE has anything to do with Ethernet?
ELTE is a fake name that was used by the nomenclature group to as a place
holder for a non-muxing LTE. The ELTE is refereeing to the new class of
SONET/SDH optical switch gear that has been developed specifically to
support high bandwidth concatenated services. There are several telephony
vendors that are developing this equipment with the view to start deployment
this year to support the OC192C/STM64C Packet Over SONET/SDH interfaces for
Internet Routers.
Please make the assumption that SONET framing will be used. Otherwise it
will require a full greenfield development cycle and extended deployment
cycle for the long haul transport systems. This is in violation of the
objective to use existing technology where ever possible.
Thank you,
Roy Bynum
----- Original Message -----
From: Osamu ISHIDA <ishida@xxxxxxxxxxxxxxxxxxx>
To: Praveen Kumar <praveen@xxxxxxxxxxx>
Cc: <stds-802-3-hssg@xxxxxxxx>
Sent: Thursday, April 06, 2000 7:02 AM
Subject: Re: What is 802.3ae WAN-PHY?
>
> Dear Praveen,
>
> Your illumination on "preserving the notion of section, line & path"
> guided me to re-consider "How far 10GENIE can support SONET
> functionality and its overhead bytes?"
>
> The answer in my heart at present is "Everything, if you want".
>
> My careful consultation with ITU-T G.707(03/96) where SDH overhead
> bytes are defined, this was like a whole day reading of a myth
> written by Latin even to me, has now convinced me that 10GENIE can
> support almost all the OAM&P in the existing SONET/SDH infrastructure.
> In other words, if you want, the Ethernet LAN-PHY with 10GENIE can
> send/receive all the SONET/SDH OAM&P information or its equivalence
> without using SONET frame.
>
> Only exception is the B2 bytes in line overhead; bit interleaved
> parity (BIP) 1536 (= 8*192 bits). The B2 bytes enable us to monitor
> the Line bit-error-rate (BER) of 10^-3 or lower, whereas the B1 byte
> (Section BIP8) or B3 byte (Path BIP8) supports BER of 6*10^-6 or
> lower. I do not believe this sensitivity up-grade is worth consuming
> 192 bytes per 100 Ethernet Packets.
>
> Of course I know we need some mapping or conversion in ELTE; one
> example is the bit-error-rate monitor that will be equivalently
> supported by the 8B/10B code violation or the 64/66 two-bit-header
> violation monitor. However, at present, I see no significance in
> these mapping/conversion issues if we remind the fact that LAN-PHY
> with 10GENIE is a real Uni-PHY; no physical WIS (SONET framer).....
> No, this is not true, we still need WIS for 10GENIE ordered-set
> insertion/removal, but I think this is much simpler than the SONET
> framer.
>
> As for the ratio of overhead to payload, I do not think it
> unpredictable. What Mr. Shimon Muller proposed in Albuquerque is
> that we have minimum guaranteed IPG bandwidth in the average, isn't
> it? Furthermore, if we carriers want, we can choke the MAC rate to
> steal the customer's bandwidth :-). What a nice system Shimon has
> invented!
> http://grouper.ieee.org/groups/802/3/ae/public/mar00/muller_1_0300.pdf
>
> Anyway, I greatly appreciate your interest on the 10GENIE approach.
>
> Best Regards,
> Osamu
>
> http://grouper.ieee.org/groups/802/3/10G_study/email/msg01965.html
> http://grouper.ieee.org/groups/802/3/10G_study/email/msg01968.html
> http://grouper.ieee.org/groups/802/3/10G_study/email/msg01971.html
>
> At 7:59 PM +0900 00.4.5, Osamu ISHIDA wrote:
> > Jonathan, Praveen,
> >
> > Thank you for your feedback.
> >
> > (1) I want to know "Why SONET framing" just for the short jumper to
ELTE.
> > How it acieves "low cost" WAN access? What is its basis?
> > Any perspective on the SONET framer side would be greatly
appreciated.
> >
> > (2) I do not see any critical issues regarding the amount of OAM&P data.
> > I do not expect full-SONET compatibility in 10GENIE, especially here
> > in 802.3ae. But even in full compatibility, SONET overhead bytes
> > defined for OAM&P are less than 30 bytes/125us(=155,520 bytes) if we
> > exclude the 192 bytes for B2 (Strong bit-interleaved parity for
Line).
> > This includes all section/line/path overhead bytes except the B2.
> > 30 bytes for every 100 Ethernet Packets (=100 IPG) sounds easy to
me.
> >
> > Best Regards,
> > Osamu
> >
> > At 11:21 AM -0700 00.4.4, 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
> >>>IPG?
> >>
> >> 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?
> >>
> >> -Praveen
>