Re: [EFM-OAM] RE: Unidirectional OAM & Clause 46
Kevin,
I tend to agree with Eric on this one. The sentence isn't particularly clear
regarding when the column of idles is sent. Perhaps the following
modification
to the sentence, and moving the sentence to just before "In the absence
of...",
"After a MAC frame and before transition to generation of
Remote Fault Sequence the RS shall ensure a column of idles
has been sent."
The frame length is not an issue for Clause 46. These changes to Clause 46
enable the unidirectional transmission of OAM frames but in no way limit
the frames to OAM. This is still done in Clause 57. Here, it should state
clearly that, when the link is lost, the OAMPDU frame size reverts back
to 64 octets as you can no longer be sure who you're OAM partner is and
so therefore can no longer use any previously shared OAMPDU max frame size.
You may choose to add wordage to the system consideration clause that
longer frames over a link using XAUI or LX-4 may not adequately propagate
the Remote Fault condition.
Thanks for requesting additional input, even though we can't vote directly
on these issues in our absence. I'll look forward to commenting on D1.5.
Regards,
Ben
Eric Lynskey wrote:
>I'm not sure if I am completely comfortable with that, but it's better than
>what is currently in there, which is nothing. Please note that this will
>also require a new PICS item to be added, or at least a modification of item
>LF4. There are several PICS items that need to be added under the optional
>OAM item.
>
>Also, if that sentence is added at the end of bullet b, then it's not
>entirely clear what happens when no MAC frames are present. Does the RS
>precede each remote fault with a column of idle, or just the first one?
>
>The other issue, which I don't think I got a clear answer on, was the size
>of frames that can be sent while in the unidirectional mode. Remembering,
>that if these frames get too large (128*4 and less than that for a XAUI
>link) then the RS will not properly see the fault condition. That is
>something that cannot be changed without a change to the counters in clause
>46.
>
>- Eric
>
>
>
>>-----Original Message-----
>>From: Kevin Daines [mailto:Kevin.Daines@worldwidepackets.com]
>>Sent: Monday, May 12, 2003 5:56 PM
>>To: benjamin.brown@ieee.org
>>Cc: Eric Lynskey; stds-802-3-efm-oam@ieee.org
>>Subject: Unidirectional OAM & Clause 46
>>
>>
>>All,
>>
>>Yesterday in the OAM STF we came up with the following text as a
>>remedy for the editor's note on the bottom of page 104 EFM
>>D1.414/Clause 46.3.4.3:
>>
>>---
>>RESPONSE:
>>
>>Add the following sentence at the end of bullet b):
>>
>>"Before transition to generation of Remote Fault Sequence the RS
>>shall ensure a column of idles has been sent."
>>---
>>
>>Even though non-attendees don't have a vote (as Bob Grow reminded
>>me), I would like to get any feedback from the OAM reflector.
>>
>>kevind
>>
>>
>
>
>
>
--
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Benjamin Brown
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