Nokia 7210 - Page 272

System Management
272
7210 SAS-M, T, R6, R12, Mxp, Sx, S Basic System
Configuration Guide
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Use subject to Terms available at: www.nokia.com
3HE 17358 AAAB TQZZA
Figure 24 Logical Model of Synchronization Reference Selection on 7210 SAS
When the CES MDA is used on the 7210 SAS-M (all variants), in addition to the
preceding references, the recovered clock derives the timing from either of the
following references:
• T1/E1 CES channel (not available for node reference)
• T1/E1 port (for loop-timing; not available for node reference)
On the 7210 SAS-Mxp, 7210 SAS-R6, 7210 SAS-R12, and 7210 SAS-T, in addition
to PTP and SyncE references, the recovered clock can be configured to derive the
timing (frequency reference) from the BITS interface.
When quality Level (QL) selection mode is disabled, the reversion setting controls
when the central clock can reselect a previously failed reference.
Table 30 lists the selection followed for two references in both revertive and non-
revertive modes.
26997
SyncE
1588
T1/E1
ref1
BITS
Output
Selector
Internal
(Node)
Timing
Reference
BITSout
T1/E1
2048 kHz
ref2
ptp
BITSin
Quality Level Override
T1/E1 BITSin
Qualifier
Qualifier
Qualifier
Qualifier
Qualifier
Quality
Level (QL)
Quality
Level (QL)
Quality
Level (QL)
Quality
Level (QL)
Quality
Level (QL)
Mode 1) Priority
reference order
Mode 2) QL then
priority reference
order
Reference
Selector
Digital Phase
Locked Loop
(DPLL)