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Re: headless chicken




Osamu,

I agree with most of your suggestions. Please allow me to re-iterate them to
insure our level of understanding:

1) Link_status is already defined as Status register bit  

Osamu ISHIDA wrote:
> 
> Rich,
> 
> Thanks for your clear definition of Break Link and Remote Fault.
> 
> My point has been that we had better specify the two management
> register bits advertised by Link Signaling; RemoteFault of the
> STATUS register bit (Local Sync Up/Down), and BreakLink of the
> CONTROL register bit (Local Isolate or something else).  I believe
> that this two-bit advertising allows us flexible PHY implementation
> yet preserving the strict Ethernet inter-operability.
> 
> Also it would be a good idea to define the Link Status bit in the
> status register to indicate 'Duplex Link Up with valid MAC partner'.
> I think this status bit shall be implemented with a latching
> function, such that the occurrence of a NotOK condition will
> be remained until it is read via the management interface.
> 
> I agree with your definition below except the BL priority.
> The LSS Link Status Code reported once ever 125 usec will carry 3-bit
> information even with minimum 4-bit Hamming protection, and hence
> RemoteFault and BreakLink can be advertised simultaneously.
> I don't see any requirement to give priority to BreakLink over
> RemoteFault.  Either or both of them causes Link Status NotOK.
> 
> Best Regards,
> Osamu
> 
> At 18:54 00/06/27 -0700, Rich Taborek wrote:
> http://grouper.ieee.org/groups/802/3/10G_study/email/msg02825.html
> > However, I urge you to keep the LSS protocol simple and not include any
> > implementation specific features. My view of Remote Fault (RF) and Break Link
> > (BL) protocol is as follows:
> >
> > Remote Fault:
> > - LSS signals RF whenever the link, including all lanes, is not synchronized;
> > - LSS RF signaling occurs once every 125 usec +/- 14 usec;
> > - Received RF is indicated in a management register (TBD).
> >
> > Break Link:
> > - LSS signals BL upon management initiative;
> > - BL has priority over RF;
> > - LSS BL signaling occurs once every 125 usec +/- 14 usec;
> > - Received BL is indicated in a management registers (TBD).
> >
> > Link Status:
> > - Set to OK when the link, including all lanes, is synchronized; and,
> > - RF or BL is not being received;
> > - Set to FAIL otherwise.
> 
> > Osamu ISHIDA wrote:
> > http://grouper.ieee.org/groups/802/3/10G_study/email/msg02810.html
> > >
> > > Local Device #1                           Remote Device #2
> > >
> > >    MAC                                               MAC
> > >     |   STA #1                         STA #2         |
> > >    PHY  Register                       Register      PHY
> > >     |    Local State                    #1 State      |
> > >     |     Sync Up/Down --(RemoteFault#1)---->         |
> > >     |     Isolate      ---(BreakLink#1)----->         |
> > >     |    Remote State                   #2 State      |
> > >     |             <----(RemoteFault#2)-- Sync Up/Down |
> > >     |             <-----(BreakLink#2)--- Isolate      |
> > >     |_________________________________________________|
> 
> -----------------------------------------
> Osamu ISHIDA
> NTT Network Innovation Laboratories
> TEL +81-468-59-3263  FAX +81-468-55-1282

-- 

Best Regards,
Rich
                                      
------------------------------------------------------- 
Richard Taborek Sr.                 Phone: 408-845-6102       
Chief Technology Officer             Cell: 408-832-3957
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