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RE: [EFM] 802.3ah OAM question


That is the problem of assumptions.  For bidirectional on a single fiber 
yes, for "rings" the up link and the down link can be very 
different.  There may the same "port", but the uplink laser is not the same 
as the down link laser, the same for the receiving optics.  Also the 
encode/decode take separate path even if it is in the same chip.

Thank you,
Roy Bynum

At 08:25 AM 2/19/2004, Shahram Davari wrote:
>Hi Roy,
>What is the advantage of knowing that the problem is forward or reverse
>direction. As far as I know in Ethernet both direction pass through the same
>path and same ports.
>-----Original Message-----
>From: Roy Bynum []
>Sent: Wednesday, February 18, 2004 5:59 PM
>To: Shahram Davari;
>Subject: Re: [EFM] 802.3ah OAM question
>Think about it.  If the remote node, in loop back mode can not inject
>packets, how will the local node know if any problems that might appear are
>in the down loop or in the up loop?  The purpose of the loop back is for
>testing.  The one of the purposes for OAM packets is to report
>discrepancies.  From a troubleshooting view, one without the other is only
>half of the picture.
>Roy Bynum
>At 10:49 AM 2/18/2004, Shahram Davari wrote:
> >Hi all,
> >
> >Should the node, which is in loopback mode, be able to generate and inject
> >OAM packets?
> >
> >Thanks,
> >Shahram Davari