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Re: Break Link and Remote Fault


I don't believe that the biggest opposition to LSS was its OAM&P capabilities.
Many notable supporters of LSS support it because of these capabilities.
However, in order to proceed, it may be beneficial to separate the "transport"
capabilities of LSS from its "data". LSS uses a 4-byte word not unlike config
words of 1000BASE-X for transport. Break Link and Remote Fault data are coded
into LSS words. OAM&P data is likewise coded.

It will take some work ensure that LSS OAM&P data is compatible with SONET OAM&P
data. If there is some fear that this work will delay the definition of LSS
Break Link and Remote Fault, then it may be reasonable to separate this from the
base LSS proposal. I believe that the current proposal allows this separation
since it provides no way to insure SONET OAM&P compatibility. 

"Booth, Bradley" wrote:
> Seto,
> I think that you're on the right track, but let's not forget that in the
> scenario of Break Link, 1000BASE-X doesn't give a damn about what is being
> transmitted.  In other words, BL can be signaled in the middle of a packet,
> IPG or idle stream.  In 1000BASE-X, Remote Fault plays by similar rules.  I
> say similar rules because the BL of auto-negotiation is required to initiate
> an auto-negotiation process which passes the RF information.  The other big
> issue with 1000BASE-X is that RF is optional.  I think LSS addresses this by
> making it mandatory.
> I think that the LSS version of BL and RF performed a better job of these
> functions by at least waiting until the end of packet.  If either BL or RF
> is transmitted, then there is a very good chance that the MAC will have
> stopped transmitting.  In the case of BL, the DTE is breaking the link and
> therefore will stop transmissions.  In the case of RF, the DTE is unlikely
> to continue to send data if it is reporting an error in the system.
> So, I think the biggest issue was with the OAM&P capabilities of LSS.  A
> couple of options as I see it are the following:
> *       remove the optional OAM&P from the LSS proposal
> *       remove OAM&P and move the BL and RF signaling into the idle stream
> *       alter the LSS proposal to only use the idle stream for OAM&P
> *       alter the LSS proposal to only use the idle stream for all signaling
> Comments?
> Cheers,
> Brad
>                 -----Original Message-----
>                 From:   Seto, Koichiro [mailto:seto@xxxxxxxxxxxxxxxxxxxx]
>                 Sent:   Monday, July 17, 2000 2:18 PM
>                 To:     stds-802-3-hssg@xxxxxxxx
>                 Subject:        Re: Break Link and Remote Fault
>                 [Date: 07/17/2000  From Seto]
>                 Shawn,
>                 I think using MAC frame means a big change to existing MAC,
> thus not a
>                 good idea.
>                 LSS is a very solid link signaling proposal.  I think we
> should start
>                 >from LSS.  The issue is whether we should use IPG or not.
>                 - 1000BASE-X uses Configuration order set (code set) to
> communicate Link
>                 Failure, but not during IPG.
>                 - 100BASE-FX uses special code sequence to communicate
> Remote Fault, but
>                 not during IPG.
>                 I'd like to take a straw poll how many would support LSS if
> it does not
>                 mandate to use IPG.  ;-)
>                 Sincerely,
>                 Seto
Richard Taborek Sr.                 Phone: 408-845-6102       
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