Subject: RFC 2558 sonetLineCurrentStatus

From: Aaron Lawrence <[email-masked]>
Date: Mon, 10 Apr 2000 12:59:21 -0400

Hi,

I'm a little confused about the RFC 2558 sonetLineCurrentStatus OBJECT-TYPE.
If you have an loss of signal condition at the input, what would the status
be?

Aaron Lawrence
[email-masked]

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From: "C. M. Heard" <[email-masked]>
Date: Mon, 10 Apr 2000 12:54:31 -0700 (PDT)

Aaron,

You are confused because you are mixing up section ans line layers.

Loss of signal is reported in sonetSectionCurrentStatus, not in
sonetLineCurrentStatus;  the value is 6 (2 because LOS is asserted,
plus 4 because LOS implies LOF).  In and of itself, LOS does not
*directly* result in anything being set in sonetLineCurrentStatus.

That said, let me hasten to add that many implementations propagate
defects from lower layers to upper layers by simulating AIS internally,
matching what would happens in external equipment.  This is recommended
by GR-253.  For the case of LOS, the section-terminating block in some
SONET chip sets sends all-ones data to the line-terminating block, just
as would be done by an external section regenerator.  If your equipment
is implemented in this way (and it's a good idea to do so), then
sonetLineCurrentStatus would assume the value 2 because AIS-L would
be asserted as an *indirect* consequence.

Mike