Re: Rate Control & far-end WIS (Re: PMD discussion)
Ishida,
It was my understanding that XAUI was to be a copper extension, not an optical PHY. That was part of a major argument for several
months. Is this coming around again?
Thank you,
Roy Bynum
----- Original Message -----
From: "Seto, Koichiro" <seto@xxxxxxxxxxxxxxxxxxxx>
To: <ishida@xxxxxxxxxxxxxxxxxxx>; <Tom_Alexander@xxxxxxxxxxxxxx>; <rtaborek@xxxxxxxxxxx>; <praveen@xxxxxxxxxxx>
Cc: <stds-802-3-hssg@xxxxxxxx>; <Stuart_Robinson@xxxxxxxxxxxxxx>
Sent: Sunday, June 04, 2000 11:03 AM
Subject: Re: Rate Control & far-end WIS (Re: PMD discussion)
> [Date: 06/04/2000 From Seto]
>
> Ishida-san,
>
> I think your point#2 is very valid especially for the cases like attached.
>
> Also, I feel the need for link confirmation taking place right before the
> link establishment. There is no way to tell the link partner is
> recognizing the link in 10GbE at this time. Your proposing scheme would
> serve for this purpose as well.
>
> Seto
>
> >
> > Tom, Rich, Praveen,
> >
> > I think we had better separate the local Rate Control from
> > the far-end WIS implementation shown in Rich's slide #9.
> > http://grouper.ieee.org/groups/802/3/ae/public/may00/taborek_3_0500.pdf
> >
> > In summary;
> > (1) How does MAC recognize locally whether he is WAN-PHY or LAN-PHY?
> > - I like to use station management (STA) register.
> >
> > (2) If we implement far-end WIS, do we need auto-negotiation?
> > - No, but we will need 'local' auto-configuration.
> >
> > Note that I have assumed that 802.3ae adopt the Shimon Muller's
> > Open-Loop Control for the MAC rate down to 9.29 Gb/s.(Not the bit rate.)
> > http://grouper.ieee.org/groups/802/3/ae/public/may00/muller_1_0500.pdf
> >
> >
> > (1)How does MAC recognize locally whether he is WAN-PHY or LAN-PHY?
> >
> > Assuming that we have optional XAUI/XGXS, 10GbE router port
> > could be implemented in separated two parts: a router/MAC
> > package and an Attachement Unit (AU). The latter may be a
> > slot-in package or daughter card. In this case, MAC should
> > recognize whether his AU is LAN-PHY or WAN-PHY. The STA
> > register would be the promising candidate for this purpose.
> > I don't think manual setting at each AU installation is less
> > troublesome than defining/using a register bit for this auto
> > configuration.
> >
> > In my sense, this auto configuration is far from 'negotiation'.
> > MAC will check the register bit when he recognize that the
> > AU is newly installed. No timing issue. No acknowledgement.
> > I think this STA register bit is extremely useful and worth
> > for the standard.
> >
> > (2) If we implement far-end WIS, do we need auto-negotiation?
> >
> > No, I don't think so. We can use similar 'auto-configuration'
> > mechanism. LSS provides the Layer-1 information reporting
> > from far-end STA to local STA, so it could send the far-end
> > 'WIS' existence or a register bit to the local STA periodically
> > by using Link Status [r] together with Remote Fault and Break Link.
> > http://grouper.ieee.org/groups/802/3/ae/public/may00/ishida_1_0500.pdf
> > I don't think this is WAN mode 'negotiation'; it's still just a
> > reporting mechanism. No timing/speed issue here; always
> > advertising the same bit status.
> >
> > In this far-end WIS implementation, the local MAC should recognize
> > the 'far-end AU/PHY installation' event to initiate the auto-
> > configuration of his local MAC rate. Every time the Link is
> > initialized, MAC had better check his local STA register bit
> > that is reflecting the far-end WIS existence.
> >
> > In short, if the community reaches the consensus not to prohibit
> > anyone from implementing far-end WIS, LSS could provide the
> > practical solution without adding any control codes.
> >
> > Best Regards,
> > Osamu
> >
> > At 03:59 00/06/03 -0700, Richard Taborek wrote:
> > http://grouper.ieee.org/groups/802/3/10G_study/email/msg02587.html
> > > Tom Alexander wrote:
> > http://grouper.ieee.org/groups/802/3/10G_study/email/msg02568.html
> > > > - the 802.3ae objectives do not provide for any form of
> > > > autonegotiation over the link. The proposed LSS does
> > > > not include speed negotiations, nor is it likely to
> > > > be able to do so with current coding schemes.
> > >
> > > WAN mode would be configured by SMT in the same manner as other
> > > options such as flow control, etc.
> > >
> > > The primary reason for the committees rejection of Auto-Negotiation
> > > at 10 Gbps is that the preferred mode of link management is to
> > > configure a link and have the link come up in the same mode after a
> > > power event or other disturbance. There is no apparent benefit in
> > > having a 10 GbE backbone negotiate down to 1 Gbps on its own accord
> > > like a modem.
> > >
> > > LSS can easily accommodate WAN mode negotiation. I don't believe that
>
> > > we have any speeds to negotiate.
> >
> > At 19:19 00/06/02 -0700, Praveen Kumar wrote:
> > http://grouper.ieee.org/groups/802/3/10G_study/email/msg02583.html
> > > In summary, I don't see why parking the WIS on the far end will not
> > > work. That being said, Iam not sure either, about whether there
> > > are enough benefits in allowing this to be a part of the standard
> > > (it sure does cause some confusion).
> >
> >
> >
> > ---------------------------------------
> > Osamu Ishida,ishida@xxxxxxxxxxxxxxxxxxx
> > NTT Network Innovation Laboratories
> > TEL:+81-468-59-3263 FAX:+81-468-55-1282
> > ---------------------------------------
> >
>