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Re: Break Link and Remote Fault

[Date: 07/17/2000  From Seto]


I guess I put a wrong button.  

What I meant by 'not using IPG' was 'not mandating to send LSS signal once in 
some SONET compatible period'.  I have no problem with the idea, but I thought 
many other did at the plenary.  As Brad wrote, it is common in Ethernet to send 
BL/LF signal during periods you don't anticipate MAC to send packets.  I thought
 many should not have a problem with such a method.  


> Seto,
> As I see it, a transport for LSS which does not use Idle (in the absence of
> packets) or IPG (in the presence of packets) becomes an alternative link
> signaling protocol. Any such alternative link signaling protocol must still be
> robust and support the required functions of a link protocol. Depending on
> whether the link protocol must operate over a serial or parallel link, the
> following functions may be applicable: synchronization, deskew and clock
> tolerance compensation. LSS is defined atop the XAUI protocol, applicable to
> parallel links as well as 64B/66B, applicable to serial links.
> I have yet to see an alternative link signaling protocol proposed which meets
> all link protocol requirements as well as LSS does. Do you have anything
> specific in mind when you refer to an LSS protocol that doesn't use the IPG?
> A question back to you and the Task Force at large: If LSS information is
> terminated in the PHY and the MAC never knows about it, is anyone concerned
> about the fact that LSS, like XAUI and SUPI, alter the PHY representation of 
> IPG?  
> Best Regards,
> Rich
> --
> "Seto, Koichiro" wrote:
> > 
> > [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
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