RE: Failure definition w.r.t. SONET/SDH and Protection/Restoratio n

[Sasha Vainshtein <Sasha@AXERRA.com>]

Diego and all,
IMHO it is reasonable to assume that a failure is
a defect that results in sending downstream AIS
(and upstream RDI) as consequent action(s).

For SDH consecutive actions for each defect
are specified in ITU-T G.783.

Note also that for some defects the consecutive action
can be disabled by configuration. Hence I'd say that
the same defect can be a failure in one case and 
not a failure in another case. The typical example
is Trail Identifier Mismatch (TIM).

Hopefully this note will help.

Regards,
                                  Sasha Vainshtein
email:                         sasha@axerra.com <mailto:sasha@axerra.com> 
phone:                       +972-3-7569993 (office)
fax:                            +972-3-6487779
mobile:                      +972-52-8674833 


> -----Original Message-----
> From: Diego Caviglia [mailto:Diego.Caviglia@marconi.com]
> Sent: Wednesday, March 23, 2005 1:06 PM
> To: ccamp@ops.ietf.org
> Subject: Failure definition w.r.t. SONET/SDH and 
> Protection/Restoration
> 
> 
> Hi all,
>               is it defined somewhere, with respect to 
> SDH/SONET, which
> defect has to be consider as a failure?
> 
> It seems to me that for interoperability could be useful to 
> have a list of
> defect that must be considered as failure, the same applies 
> for defect that
> optionally can be considered as defect.
> 
> May be also a communication between restoration TNEs in order 
> to agree on
> the list could be useful.
> 
> Does anyone agree on that?
> 
> Regards
> 
> Diego
> 
> PS I apologise if the list is defined somewhere but I wasn't 
> able to find
> it.
> 
> 
> 
>