RE: Link Status thoughts
Lior,
/E/ would normally be transmitted when any of the physical sublayers (e.g.
a PCS or an XGXS) receives bytes that it cannot encode. For instance, if
a DTE XGXS got a byte from the XGMII that was a control byte but did not
have a valid control code or if the 10GBASE-X PCS received a byte that
had a code violation. They are normally caused by bit errors.
Also, if a sublayer receives an /E/, it will transmit an /E/.
The purpose of /E/ is to protect against an error getting turned into
a valid code that might end up producing a packet with an undetectable
error.
There are two proposals for break link and remote fault siganlling. The
802.3ae task force has not made any decision on the matter yet. By the way,
since
we have an approved project, the group is no longer called HSSG, High
Speed Study Group. A study group exists to study what project if any
should be initiated. Once the project is approved, it isn't a study
group any more.
802.3ae has not adopted any objectives for any kind of auto negotiation
protocol. All the links we have defined will initialize using the
normal data signals -- no training signals are needed.
Pat Thaler
-----Original Message-----
From: Lior Reem [mailto:LReem@avaya.com]
Sent: Monday, October 30, 2000 7:23 AM
To: 'rtaborek@earthlink.net'
Cc: 'HSSG'
Subject: RE: Link Status thoughts
Hi Rich,
1. Can you explain in which cases /E/ is transmitted onto the XAUI
interface, and how should the receiver react in these cases?
2. Are there any agreements in the HSSG about Remote Fault and Break Link
signaling?
3. Any thoughts about Link Initialization?
These questions are mainly a concern for cross-connect equipment which work
in low levels, but need to supply solutions in broken link cases.
Thanks,
Lior.
~~~~~~~~~~~~~~~~~~
Lior Re'em
Avaya Inc.
Israel
Tel : +972 3 6457608
Email : lreem@avaya.com
~~~~~~~~~~~~~~~~~~
> -----Original Message-----
> From: Rich Taborek [SMTP:rtaborek@earthlink.net]
> Sent: ℷ &alef;&vav;&qof;&tet;&vav;&bet;&resh; 31 2000 10:53
> To: HSSG
> Subject: Re: Link Status thoughts
>
>
> Isaac,
>
> P802.3ae has no Auto-Negotiation objective and Auto-Negotiation was
> voted down at the September, 2000 meeting. Current P802.3ae definitions
> set Link Status = OK when the transmitter is operational and the
> receiver can synchronize to the incoming bit stream and signal detect is
> OK. Any "close loop" or handshaking of the two simplex links must be
> initiated at the MAC level or above. This is true for all P802.3ae
> variants including LAN and WAN and is independent of coding and the
> presence or absence of any interfaces or extensions.
>
> Best Regards,
> Rich
>
> --
>
> Isaac Fuchs wrote:
> >
> > Hi Rich
> > As I know from 802.3z link_status is a close loop
> > information. It's mean that link_status is up only when
> > both sides transmit and also receive right symbols (c1,c2)
> > [I know that 802.3z includes also auto_neg.].
> > Is there in P802.3ae any close loop (LAN application)?
> > I mean when I transmit after powering on /K/R/.. from XGXS layer how
> can I
> > know that the remote receive this information?
> > Regards
> > Isaac Fuchs
>
> -------------------------------------------------------
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> Chief Technology Officer Cell: 408-832-3957
> nSerial Corporation Fax: 408-845-6114
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