Transmission protection
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Supported protection mechanisms
To guarantee service availability, these transmission protection mechanisms are
supported by the Metropolis
®
AMU:
•
Multiplex Section Protection (MSP) 1 + 1
–
1+1 MSP protection for optical and electrical STM-1 and optical
STM-4/STM-16 interfaces.
The protection switching can be configured revertive and non-revertive as well
as unidirectional and bidirectional (i.e. both directions of transmission are,
respectively, switching separately or jointly). But the remote end of the
Multiplex section must support the necessary features for this operation. Any
STM-N port combination with the same transmission rate can be used as a
combination of line and tributary SDH ports.
Forced, manual and lockout switch commands are supported. The MSP
implementation is compliant with the ITU-T Rec. G.841/Clause 7.1 and ETS
300417-3-1 (i.e. the APS protocol is optimized for 1:N protection). ETSI failure
of protocol applies. Under this protocol also an alarm-free interworking mode
with SONET defined MSP is supported.
The maximum switch completion time is 50 ms.
•
Subnetwork Connection Protection (SNCP)
–
VC-12 SNC/N protection (non-revertive)
A non-intrusively monitored subnetwork connection protection (SNC/N) relation
can be set up between any arbitrary incoming TU-12 from any STM-N and any
other arbitrary incoming TU-12 from any STM-N interface (VC-12s are
mapped into TU-12s).
Only non-revertive operation is possible. Manual and forced switch commands
are supported. In the return channel the signal is simply bridged to both
outputs.
The maximum switch completion time is 50 ms.
–
Lower order VC-3 SNC/N protection (non-revertive)
A non-intrusively monitored subnetwork connection protection (SNC/N) relation
can be set up between any arbitrary incoming TU-3 from any STM-N interface
and any other arbitrary incoming TU-3 from any STM-N interface.
Only non-revertive operation is possible. Manual and forced switch commands
are supported. In the return channel, the signal is simply bridged to both
outputs. note that hardware based SNCP switching for can be implemented for
lower order VC-12 and VC-3s.
The maximum switch completion time is 50 ms.
–
Higher order VC-4 SNC/N protection (non-revertive)
A non-intrusively monitored subnetwork connection protection (SNC/N) relation
can be set up between any arbitrary incoming TU-3 from any STM-N interface
and any other arbitrary incoming TU-3 from any STM-N interface.
Only non-revertive operation is possible. Manual and forced switch commands
are supported. In the return channel the signal is simply bridged to both
outputs.
The maximum switch completion time is 50 ms.
Features
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365-312-847R4.0
Issue 4, November 2006
Lucent Technologies - Proprietary
See notice on first page
3-17