Forcibly Specifying A Reference Clock Source; Establishing The Configuration Task - Huawei Quidway S9300 Configuration Manual

Quidway S9300 Terabit Routing Switch
Configuration Guide - Device Management
l
l
l
Clock Source Selection Mode Supported by the S9300
The S9300 supports the follow modes of clock source selection:
l
l
l
The SSM quality level takes precedence over the priority when the SSM quality level is used in
clock source selection. In forcible mode, you can specify a clock source regardless of the SSM
quality level and priority of the clock source. In manual mode, you can specify a clock source
regardless of the priority of the clock source, but the SSM quality level still affects the selection
result.
If you enable the result of frequency offset check to affect clock source selection, the selection
result also depends on the result of frequency offset check. If the frequency offset of a clock is
out of the specified range, the signal of the clock is considered invalid (Signal-fail), and the clock
cannot be selected as the clock source.

11.3 Forcibly Specifying a Reference Clock Source

The S9300 allows you to forcibly specify a reference clock source flexibly.

11.3.1 Establishing the Configuration Task

Before forcibly specifying a reference clock source, familiarize yourself with the applicable
environment, complete the pre-configuration tasks, and obtain the required data.
Applicable Environment
Generally, the system selects the clock source automatically. You can forcibly select the clock
source of a clock in special situations.
You can forcibly specify a clock source regardless of the SSM quality level and priority of the
clock source. Different from the manual mode, you can specify a clock source in Signal-fail
state in forcible mode.
Issue 03 (2011-12-29)
An external clock can function as the reference clock source of other clocks or send clock
signals. Other clocks can function only as the reference clock of external clocks.
The system clock can select the reference clock source among clocks 0 to 8.
The BITS clocks can select clocks 5 to 9 as the reference clock source.
Free running
– Non-SSM mode: The clock source is selected based on the priority. A smaller priority
level indicates a higher priority.
– SSM mode: The clock source is selected based on the SSM quality level and priority.
The SSM quality level takes precedence over the priority in clock source selection.
The clock source with the highest SSM quality level is selected first.
When two clock sources have the same SSM quality level, the one with higher priority
is selected.
– SSM extended mode: This mode is based on the SSM mode, and you can set the clock
source ID in this mode.
Forcible mode
Manual mode
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
11 Ethernet Clock Syntonization Configuration
166