Marconi OMS 1200
Technical Product Description
221 02-ZAP 701 25/1 Rev C 2006-08-04
© Ericsson AB 2006
03PHB00004AAV-CUA
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Note:
In bi-directional operation, when using the ITU-T/ETSI standard protocol,
you can only select the protection channel if, in addition to an appropriate
indication being received, the transmitted K1 byte (bits 5-8) and received K2
byte (bits 1-4) are the same.
If a transmitted K1 byte indication and received K2 byte indication do not
match, the selector stays released (selecting the working channel) and an
alarm is raised. This does not apply in unidirectional mode. Operation of the
K1, K2 byte signalling is described in Section 7.4.21.
When using the Siemens protocol, selection of the protection channel is performed
automatically. However, if the received K2 byte (bits 1-4) does not match the locally
selected channel within 1 second (1000ms), an alarm is raised, and the selector
released.
Table 7-9: MSP Switch Indications
Priority Indication
Received (Note 1)
Selected Channel
1 Forced
Switch
(Protection)
Working
2
Signal Fail
(Protection)
Working
3 Forced
Switch
(Worker Channel)
Protection (Note 3)
4
Signal Fail
(Worker Channel)
Protection (Note 3)
5 Signal
Degrade
(Protection)
Working
6 Signal
Degrade
(Worker Channel)
Protection (Note 3)
9
Wait to Restore
(Worker Channel)
(Notes 2,4)
Protection (Note 3)
10
Do not Revert
(Worker Channel)
(Notes 2,5)
Protection (Note 3)
11 No
Request
(Protection) (Note 2)
Working (Revertive Mode)
or
Working Or Protection
(Non-Revertive Mode)
Note:
1
: Only local indications apply in unidirectional mode. In bi-directional mode
both local and remote indications apply. Remote indications are signalled via
the K1 byte. A local indication has a higher priority than a remote indication
of the same type. If a local and a remote indication of the same type are
received simultaneously the local indication is active.
Note:
2
: Only the protection channel may be specified for a No Request indication.
Only the working channel may be specified for Wait to Restore and Do not
Revert indications.