AIS (RE: WIS OH)
Dave, Pankaj,
Thanks for your information. Yes, that is exactly what I wanted
to know. I think that these alarming reactions in WIS should also
be documented in 802.3ae.
All,
I asked the question since I was not sure whether ELTE on the
Ethernet side is lit on or not when its SONET side receives
such AIS signals. Shutting down the light is the simplest
way to notify the remote fault to WIS, but it prevents WIS
from localizing the fault location.
Here I see the similar issue in 40km+ LAN-PHY Link, especially
when implemented with optional XAUI interface.
Let me assume that the far-end (remote) PHY is implemented as
an independent PHY package connected with a MAC/router package
via backboard XAUI interface.
Then what happens if the MAC/router package is shutting down or
broken down? Should the PHY package be shutting down at the
same time? Or can we design the PHY package to be kept lit on
and just sending the AIS (Alarm Indication Signal) without
breaking the Layer-1 connection?
From the view point of fiber plant management, I hope that the
latter implementation, the PHY package beeing kept lit on
regardless of its valid XAUI connection or not, would be allowed
in the 802.3ae standard. This helps us to localize the fault
location; Layer-1 link or far-end MAC. Also Layer-1 link
performance can be monitored continuously if it is required
for our SLA.
However, I am not sure that this implementation is allowable
or not in 802.3 tradition/standardization. If you see some
issues in this type of implementation, please let me know the
problems.
Best Regards,
Osamu
At 09:34 00/06/09 -0700, Pankaj Kumar wrote:
http://grouper.ieee.org/groups/802/3/10G_study/email/msg02643.html
> In the WAN PHY, Beside the line AIS ( With K2 byte processing )
> and path AIS ( Pointer bytes processing ), Other SONET/SDH higher
> layer ( Section, Line ) alarms like Loss of signal ( LOS), Loss of
> Sonet/SDH frame etc should Disable the 66/64 Decoder and the Loss
> of Delineation defect should be detected , Then MAC will discard
> frame.
At 09:57 00/06/09 -0400, David Martin wrote:
http://grouper.ieee.org/groups/802/3/10G_study/email/msg02640.html
> Your description is correct. If you're asking how the WAN PHY
> will react to Line/Path AIS, the pointer processor will detect
> AIS-P and the all ones signal will be passed from the WIS up to
> the 66/64 decoder, which will lose sync (e.g. LOD defect, Loss
> Of Delineation), then the MAC will see the ReceiveDataValid
> line inactive & discard frames.
At 19:24 00/06/09 +0900, Osamu ISHIDA wrote:
http://grouper.ieee.org/groups/802/3/10G_study/email/msg02636.html
> Could you help me to understand how WAN-PHY and ELTE would react on
> SONET AIS (Alarm Indicaton Signal)?
>
> When we have cable cut in SONET infrastructure, the SONET side of
> the ELTE will receive either Line-AIS or Path-AIS.
>
> Line-AIS: all '1' in Line OH and SPE payload.
> generated by the regenerator who detect upstream cable cut.
> detected by the last 3 bits in K2 (at least 3 consecutive '111')
>
> Path-AIS: all '1' in AU pointer and SPE payload.
> generated by LTE who detect upstream cable cut.
> detected by the all '1' in H1&H2 at least 3 consecutive frames.
>
> Thank you,
> Osamu
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Osamu Ishida,ishida@xxxxxxxxxxxxxxxxxxx
NTT Network Innovation Laboratories
TEL:+81-468-59-3263 FAX:+81-468-55-1282
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