Unidirectional path-switched ring switching
....................................................................................................................................................................................................................................
Overview
Metropolis
®
DMXplore supports path switched ring applications in
accordance with the path protection switching schemes described in
Telcordia Technologies GR-1400.
Metropolis
®
DMXplore performs UPSR switching in response to
automatically detected faults in paths and external commands from a
WaveStar
®
CIT or operations system (OS). Metropolis
®
DMXplore
supports UPSR switching for VT1.5 and STS-N signals on OC-3 and
OC-12 interfaces.
Path protection switching functions are available from the WaveStar
®
CIT System View menu when you select
Fault
→
Protection Switch
.
Path protection switching can also be controlled using the command
builder and the
opr-protnsw-sts1
,
opr-protnsw-sts3c
, and
opr-protnsw-vt1
commands.
Protection switching
priorities
The following table shows the UPSR protection switch priorities (in
descending order of priority) used by Metropolis
®
DMXplore.
Table 4-2
UPSR switch priorities
Switch Priorities (Descending Order)
Source of Request
Reset
WaveStar
®
CIT or OS
Lockout of Protection
WaveStar
®
CIT or OS
Forced Switch
WaveStar
®
CIT or OS
Automatic Switch: Signal Failed
Automatic
Automatic Switch: Signal Degrade
Automatic
Manual Switch
WaveStar
®
CIT or OS
Automatic path selector
criteria
Metropolis
®
DMXplore performs automatic UPSR switching based on
the automatic path selector criteria. The automatic path selector
criteria uses the following hierarchy of signal impairments (ordered
from top to bottom in increasing signal quality):
•
line LOS, LOF, AIS, STS and VT path AIS, LOP, and UNEQ
(most impaired - worst signal quality)
•
STS-N and VT Path BER exceeding a signal degrade threshold
•
Path-level signal with no impairments.
Maintenance overview
....................................................................................................................................................................................................................................
365-372-333 R2.1
Issue 4, June 2005
Lucent Technologies
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