H3C S9500 Series User manual

Operation Manual – Clock Monitoring
H3C S9500 Series Routing Switches Table of Contents
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Table of Contents
Chapter 1 Clock Monitoring Configuration.................................................................................1-1
1.1 Clock Monitoring Module Overview...................................................................................1-1
1.1.1 Introduction to Clock Monitoring Module.................................................................1-1
1.1.2 Classification of Clock Sources...............................................................................1-2
1.1.3 Reference Source Level..........................................................................................1-2
1.1.4 Working Mode of the Clock Monitoring Module of the SRPU.................................1-3
1.1.5 Working Mode of the Port Clock .............................................................................1-3
1.2 Clock Monitoring Module Configuration Task List.............................................................1-4
1.3 Configuring Working Mode of the Clock Monitoring Module of the SRPU........................ 1-5
1.4 Configuring Reference Source Priority.............................................................................. 1-5
1.5 Configuring SSM for Reference Sources ..........................................................................1-5
1.5.1 Setting the Way of Deriving SSM Level..................................................................1-5
1.5.2 Setting the Bit Position for Transmitting Bits Clock Source Information................. 1-6
1.5.3 Configuring SSM Levels for the Reference Source................................................1-6
1.5.4 Activating/Deactivating SSM...................................................................................1-7
1.6 Stopping the Clock Monitoring Module from Warming Up ................................................1-7
1.7 Setting the Input Port of the Line Clock (LPU Port)...........................................................1-7
1.8 Displaying and Maintaining Clock Monitoring Module.......................................................1-8
1.9 Clock Monitoring Module Configuration Example..............................................................1-9

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Chapter 1 Clock Monitoring Configuration
When configuring clock monitoring module, go to these sections for information you are
interested in:
zClock Monitoring Module Overview
zClock Monitoring Module Configuration Task List
zConfiguring Working Mode of the Clock Monitoring Module of the SRPU
zConfiguring Reference Source Priority
zConfiguring SSM for Reference Sources
zStopping the Clock Monitoring Module from Warming Up
zSetting the Input Port of the Line Clock (LPU Port)
zDisplaying and Maintaining Clock Monitoring Module
zClock Monitoring Module Configuration Example
1.1 Clock Monitoring Module Overview
This section covers these topics:
zIntroduction to Clock Monitoring Module
zClassification of Clock Sources
zReference Source Level
zWorking Mode of the Clock Monitoring Module
zWorking Mode of the Port Clock
1.1.1 Introduction to Clock Monitoring Module
Clock monitoring module is responsible for providing highly-precise, highly-reliable
SDH (synchronous digital hierarchy) line interface 38.88 MHz clock signals for different
service interface cards. It implements such functions as input clock source automatic
selection, software phase-lock, and real-time monitoring of the clock status of the
interface card.
Currently, the clock monitoring module supports 18 reference clock sources (referred to
as reference source hereafter), among which the first and the second are Bits clock
sources and others are line clocksources. Each reference source corresponds to a slot.
The specific relationship is decided by device hardware. The following figure shows the
reference-slot relationship of the S9500 series switches:

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H3C S9500 Series Routing Switches Chapter 1 Clock Monitoring Configuration
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S9502
S9505
S9508
S9512
S9502
S9505
S9508
S9512
Figure 1-1 Relationship between reference source and slot
1.1.2 Classification of Clock Sources
Clock sources can be classified into three categories according to different sources of
the clock source of the clock monitoring module:
zLocal clock source: 38.88 MHz clock signals generated by a crystal oscillator
inside the clock monitoring module.
zBits clock source: clock signals generated by a Bits clock device. The signals are
sent to the clock monitoring module through a specific interface on the SRPU
(switch and router processing unit) and then sent to all interface cards by the clock
monitoring module.
zLine clock source: clock signals provided by the upper level device. Its precision is
lower than Bits clock source. The signals are derived from the specific WAN
interface and then sent to the clock monitoring module, which sends the signals to
all interface cards in turn.
1.1.3 Reference Source Level
The reference source level is decided together by the priority and the synchronization
status marker (SSM) level of the reference source.
I. Priority of the reference source
You can set a high priority for the reference source with high-precision and
high-reliability to make it be selected as the clock source with precedence.
II. SSM level of the reference source
SSM, also known as synchronization quality marker, is used to indicate the
synchronization timing signal level on a synchronization timing transmission link.
The priority of SSM level of the reference source, ranging from high to low includes:
zPRC: G.811 clock signal
zTNC: G.812 transit node clock signal
zLNC: G.812 local node clock signal
zSETS: SDH device clock source signal
zunknown: Unknown synchronization quality

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zDNU: DoNotUse
The reference source whose SSM level is DNU cannot be used as a clock source.
1.1.4 Working Mode of the Clock Monitoring Module of the SRPU
The working mode of the clock monitoring module is also the mode it adopts to choose
the clock source, including the manual mode and the auto mode.
I. Manual mode
In this mode, the clock source is configured manually. The clock monitoring module
does not switch the clock source automatically, but just tracks the user-configured
primary reference source. If the primary reference source is lost, the clock monitoring
module enters a hold state.
II. Auto mode
In auto mode, the clock source is selected by the system automatically. When the
primary clock source is lost or in free run status, the clock monitoring module selects
another clock source based on the following rules:
zIf SSM level is not activated, the clock source is decided by reference source
priority. If two reference sources have the same priority, the one with the smaller
reference source number (1 to 18) is selected. When the reference source with the
highest priority is missing, the next available reference source with the highest
priority is selected. When the former clock source becomes available, the system
switches to that clock again.
zIf SSM is activated, the clock source is decided by the SSM level. If two reference
sources have the same SSM level, the referencesource priority takes effect, in the
way described above.
Note:
The following clock sources are excluded in clock selection (when SSM is activated):
zClock sources whose signals are missing;
zClock sources whose priority is 255. By default, the priority of all clock sources is
255.
zClock sources whose SSM level is DNU (DoNotUse).
1.1.5 Working Mode of the Port Clock
Depending on the source of the port clock, a port of an S9500 series switch supports
two clock modes:

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I. Master mode
In this mode, the system uses the clock signals provided by the clock monitoring
module. The signals include local clock signals and clock signals derived from LPU Port.
If you have configured on the device to derive clock signals from LPU Port, these
derived signals are adopted; otherwise, local clock signals are adopted.
II. Slave mode
In this mode, the system uses line clock signals. Only when you specify a port as the
LPU Port (clock signal input port) of the device can the system derive the clock source
from the line signals received on the port and then send the clock source information to
the clock monitoring module, which then sends the information to all interface cards.
When connected to SONET/SDH switches, a switchshould be configured as to work in
slave clock mode, because the SONET/SDH network clock is more precise than that of
the switch.
1.2 Clock Monitoring Module Configuration Task List
Note:
The following configurations are applicable to the S9500 series Ethernet switches
whose SRPU is installed with a clock module. For information about the SRPUs
installed with a clock module, refer to Installation Manual.
Complete these tasks to configure clock monitoring module:
Task Remarks
Configuring Working Mode of the Clock Monitoring Module of the
SRPU Optional
Configuring Reference Source Priority Optional
Setting the Way of Deriving SSM Level Optional
Setting the Bit Position for Transmitting Bits Clock
Source Information Optional
Configuring SSM Levels for the Reference Source Optional
Configuring
SSM for
Reference
Sources
Activating/Deactivating SSM Optional
Stopping the Clock Monitoring Module from Warming Up Optional
Setting the Input Port of the Line Clock Optional

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1.3 Configuring Working Mode of the Clock Monitoring
Module of the SRPU
To do… Use the command… Remarks
Enter system view system-view —
Configure the work mode
of the clock monitoring
module
clock { auto | manual
source source-number }Optional
Auto mode by default
1.4 Configuring Reference Source Priority
In auto mode, the clock monitoring module selects a reference source based on SSM
level and reference source priority.
Follow these steps to configure reference source priority:
To do… Use the command… Remarks
Enter system view system-view —
Configure the reference
source priority clock priority value
source source-number Required
255 by default.
1.5 Configuring SSM for Reference Sources
1.5.1 Setting the Way of Deriving SSM Level
You can use the following two ways to derive the SSM level of a reference source:
zThe interface card derives the SSM level from the Bits clock source, and reports
the SSM level to the SRPU, which sends the SSM level to the clock monitoring
module.
zOr you can configure SSM level as needed, as shown in the table in Configuring
SSM Levels for the Reference Source:
Follow these steps to set the way of deriving SSM level:
To do… Use the command… Remarks
Enter system view system-view —
Set the way to derive SSM
level
clock forcessm { on |
off } source
source-number
Optional
By default, the SSM level
is set by users.

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1.5.2 Setting the Bit Position for Transmitting Bits Clock Source Information
The bits for transmitting Bits clock source information can be configured as sa4, sa5,
sa6, sa7 and sa8. They are 5 bits in timeslot 0 of the even frame in a multi-frame as
specified by ITU-TG.704 CRC4. The network administrator can choose one from the
five bits to carry SSM information.
Follow these steps to set the bit for transmitting Bits clock source information:
To do… Use the command… Remarks
Enter system view system-view —
Set the bits for
transmitting the Bits clock
source information
clock sa-bit { sa4 | sa5 |
sa6 | sa7 | sa8 } source
source-number
Optional
sa4 is the default bit for
transmitting the Bits clock
source information.
1.5.3 Configuring SSM Levels for the Reference Source
Follow these rules to manually set the SSM level for the clock source:
zFor the line clock source, the SSM level configured is that of the clock source.
zFor Bits clock source, if the input signal is a 2048 kbps (E1) signal and the clock
forcessm off source is executed, the clock source adopts the SSM level derived
from the input signals and the SSM configured is omitted.
zFor Bits clock source, if theinput signal is a 2048 KHz signal or a 2048 kbps signal
and the clock forcesssm on source command is executed, the clock source
adopts the SSM level configured.
Follow these steps to set the SSM level:
To do… Use the command… Remarks
Enter system view system-view —
Set the SSM level of the
reference source
clock ssm { dnu | lnc |
prc | sets | tnc |
unknown } source
source-number
Required
By default, the SSM level
of all reference sources is
unknown.
Note:
The reference source with the SSM level being DNU cannot be used as a clock source.
Therefore, it does not participate in clock source switch when the clock monitoring
module works in auto mode.

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1.5.4 Activating/Deactivating SSM
No matter the SSM levels are obtained through clock signals or configured manually,
you have to activate them before they can take effect.
zWhen SSM is activated, the SSM levels become the decisive factor in clock
source automatic selection.
zWhen SSM is not activated, you can still set and view the SSM levels, but they are
ignored in clock source automatic selection.
Follow these steps to activate or deactivate SSM:
To do… Use the command… Remarks
Enter system view system-view —
Activate/deactivate SSM clock ssmcontrol { on |
off }
Optional
SSM is deactivated by
default.
1.6 Stopping the Clock Monitoring Module from Warming Up
To do… Use the command… Remarks
Enter system view system-view —
Stop the clock monitoring
module from warming up clock stop warm-up Required
1.7 Setting the Input Port of the Line Clock (LPU Port)
To do… Use the command… Remarks
Enter system view system-view —
Set the LPU port of the
line clock
clock lpuport
{interface-type
interface-number }
Optional
By default, the clock LPU
port is the first
configurable port by port
name in alphabetical
order of the interface
board
Enter interface view interface interface-type
interface-number —
Set the LPU port to work
in Slave mode clock slave Optional
The LPU port works in
Slave mode by default.

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Note:
For a POS interface card, if you set the port clock to work in Slave mode, you must use
the clock lpuport command to set the LPU port of the clock source of the interface
card.
1.8 Displaying and Maintaining Clock Monitoring Module
To do… Use the command… Remarks
View the clock base
phase display clock
basephase
View the current
configuration of the clock
monitoring module display clock config
View the detailed
information of the clock
monitoring module display clock device
View the D/A value of the
DAC inside the clock
monitoring module display clock d/a
View the input clock
source port of the line
board display clock lpuport
View the lock state of the
clock monitoring module display clock
phase-lock-state
View the priority of all
reference sources display clock priority
View the self-test result of
the clock monitoring
module
display clock
self-test-result
View the state of all
reference sources display clock source
View the SSM level of all
reference sources display clock ssm-level
View the SSM level of the
output clock signal. display clock
ssm-output
View the clock monitoring
module version display clock version
View the work mode of the
clock monitoring module
of the SRPU
display clock
work-mode
Available in any view

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1.9 Clock Monitoring Module Configuration Example
I. Network requirements
zTwo S9508 switches Switch A and Switch B are connected through their POS
interfaces. They are equipped with the clock monitoring modules on their SRPUs,
and thus you can configure the synchronization clock parameters.
zThe synchronization clock of Switch A is provided by its clock monitoring module.
zSwitch B adopts the line clock from Switch A to synchronize with the SDH line of
Switch A.
II. Network diagram
Figure 1-2 Network diagram of system clock configuration
III. Configuration procedure
1) Configure Switch A (Master clock).
# Set the interface POS 1/1/1 to work in master clock mode, using local clock signals.
<Sysname> system-view
[Sysname] interface pos 1/1/1
[Sysname-Pos1/1/1] clock master
2) Configure Switch B (Slave clock).
# Set the LPU port on Switch B to POS 1/1/1.
<Sysname> system-view
[Sysname] clock lpuport pos 1/1/1
# Set the interface POS 1/1/1 to work in slave clock mode.
[Sysname] interface pos 1/1/1
[Sysname-Pos1/1/1] clock slave
# Enable the clock source obtained from POS 1/1/1; set the clock to work in manual
mode and use clock source 8 as the primary clock source, which corresponds to slot 1
(refer to Figure 1-1).
[Sysname] clock manual source 8
Through the above configurations, all the other POS interface cards get the same clock
frequency derived by the clock module from the line clock of POS 1/1/1. In this way, all
the service cards of the switch can get precise, reliable, synchronized SDH line
interface.