Commit 7f4c52ad authored by Adam Wujek's avatar Adam Wujek 💬

docs/specifications/management: move wrs_failures to wr-switch-sw repo

Move done to keep document synced with source.
Signed-off-by: Adam Wujek's avatarAdam Wujek <>
parent 0855671b
all : wrs_failures.pdf
.PHONY : all clean
wrs_failures.pdf : wrs_failures.tex fail.tex intro.tex snmp_exports.tex
pdflatex -dPDFSETTINGS=/prepress -dSubsetFonts=true -dEmbedAllFonts=true -dMaxSubsetPct=100 -dCompatibilityLevel=1.4 $^
pdflatex -dPDFSETTINGS=/prepress -dSubsetFonts=true -dEmbedAllFonts=true -dMaxSubsetPct=100 -dCompatibilityLevel=1.4 $^
clean :
rm -f *.eps *.pdf *.dat *.log *.out *.aux *.dvi *.ps *.toc
This document tries to list all possible ways the White Rabbit Switch can
brake. It is my brain dump and should be a starting point to improve SNMP
implementation and alarms (traps) generation. The document also tries to
describe what should be the operator's action for each failure. Whether it's
enough to reboot the switch or if it should be replaced with a new unit.
The document is organized in two parts. First one (section \ref{sec:failures})
tries to list all the possible failures that may disturb synchronization and
Ethernet switching. The structure of each failure description is the following:
\item [] \underline{Mode}: for timing failures, it says which modes are
affected. Possible values are:
\item \emph{Slave} - WR Switch has at least one Slave port synchronized to
another WR device higher in the timing hierarchy (though it may be also
Master to other WR/PTP devices lower in the timing hierarchy).
\item \emph{Grand Master} - WR Switch at the top of the synchronization
hierarchy. It is synchronized to an external clock (e.g. GPSDO, Cesium)
and provides timing to other WR/PTP devices.
\item \emph{Free-Running Master} - WR Switch at the top of the
synchronization hierarchy. It provides timing to other WR/PTP devices
but runs from a local oscillator (not synchronized to external atomic
\item [] \underline{Description}: what the problem is about, how important it
is and what bad may happen if it occurs.
\item [] \underline{SNMP objects}: which SNMP objects should be monitored to
detect the failure. These may be objects from \texttt{WR-SWITCH-MIB} or one
of the standard MIBs used by the \emph{net-snmp}.
\item [] \underline{Notes}: optional comment in case required SNMP objects are
not yet exported by our current implementation of the SNMP agent. It
describes some preliminary ideas what should be exported in the near future.
Section \ref{sec:snmp_exports} is a documentation for people integrating WR
switch into a control system, operators and WR experts. It describes all
essential SNMP objects exported by the device divided into two groups:
\emph{Operator/basic objects}, \emph{Expert objects}
\documentclass[a4paper, 12pt]{article}
\graphicspath{ {../../../../figures/} }
% creating subsubsubsection notation
% src:
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\title{White Rabbit Switch: Failures and Diagnostics}
\author{Grzegorz Daniluk\\ Adam Wujek\\[.5cm] CERN BE-CO-HT}
\section{Possible Errors}
%\section{SNMP exports}
%\subsection{Operator/basic objects}
%\subsection{Expert objects}
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