How to Configure E1/STM-1 Clock Synchronization between Huawei OLT and ONU?


When Huawei OLT MA5680T access a base station that requires only frequency synchronization, and when MA5680T are connected upstream to the Huawei SDH OSN 3500 or OSN7500 network by using the E1/STM-1 port, the E1/STM-1 line clock can be used for clock synchronization.


As shown in below figure, Huawei OLT MA5680T recovers the clock from the E1/STM-1 line. This clock is transmitted by the BSC/RNC through the SDH network and then transmitted to Huawei ONU, such as MA5628-4 through the PON line clock. After recovering the clock, the ONU transmits the clock to the base station through the E1 line.

E1/STM-1 line.png



The clock daughter board CKMC/CKMD of MA5680T main control board SCU must be in position. 




Configuration roadmap for clock synchronization:

1. MA5680T traces the upstream E1/STM-1 line clock of the TOPA board as the system clock. 

2.The system clock is delivered to an ONU MA5628-4 through optical paths of the GPON board GPFD or GPBD. 

3. The ONU MA5628-4 uses the line clock of the GPON upstream port as the system clock. 

4. The ONU MA5628-4 transmit clock is synchronized with the system clock of the ONU.



1?Configure a clock on OLT MA5680T.



1.1. Add a system clock source.

Run the clock source command to configure the line clock of E1/STM-1 port 0/5/0 on the TOPA board as the system clock source. Set the ID of the clock source to 0.

The clock module automatically judges the type of the specified clock source (E1/STM-1) and selects a reference source for phase lock based on priorities.

huawei(config)#clock source 0 0/5/0


1.2. Configure a priority for the system clock source. 

Run the clock priority command to set the priority of clock source 0 to the highest priority.

huawei(config)#clock priority system 0


1.3. Query configurations and the status of the system clock source.

Run the display clock source system command to query configurations and the status of the clock source. Ensure that configurations of the system clock source are correct, and the status is ‘Normal’.

huawei(config)#display clock source system
Index  Board    Source   Clk-type  State       Priority QL    Selected
0    H801TOPA    0/5/0    E1     Normal      0   ---   YES


Run the display clock mode command to query the clock working mode. Ensure that the clock daughter board works in tracing mode.

huawei(config)#display clock mode
Clock manage-mode:Third-mode
Clock subboard work-mode:Tracing


2.Configure a clock on the Huawei ONU MA5628-4.




2.1.Configure the GPON line clock as the system clock.

The system clock of the Huawei OLT MA5680T is delivered to the ONU through MA5680T GPON port, achieving clock synchronization between the OLT and the ONU.

Run the clock source command to configure the clock recovered from the GPON upstream port as the system clock of the ONU.

Run the clock priority command to configure the priority of the clock source.

huawei(config)#clock source 0 0/0/1
Clock source set succeeded
huawei(config)#clock priority system 0


2.2. Configure the system clock as the transmit clock for an E1 port.

Run the interface tdm command to enter the E1 port configuration mode.

Run the tx clock or port portid udt system command to configure the system clock as the transmit clock of the port.

Run the display port state command to query the transmit clock of the E1 port.

huawei(config)#interface tdm
huawei(config-if-tdm-)#port 0 udt system
huawei(config-if-tdm-)#display port state 0
Port          : 0
State         : normal
Mode          : UDT
Code          : HDB3
Looptype      : -
Timeslot      : -
Clock         : system
CRC4          : -
Signaling     : -
ESF           : -
Impedance     : 120 Ohm


2.3. Query configurations and the status of the system clock source.

Run the display clock source command to query configurations and the status of the system clock source.

huawei(config)#display clock source
Index  Config   Type   Source      State     Priority   Output
0       YES      line   0/0/1       Normal     0         YES
1       NO       --     -/ -/ -     ---        ---       ---
2       NO       --     -/ -/ -     ---        ---       ---
3       NO       --     -/ -/ -     ---        ---       ---
4       NO       --     -/ -/ -     ---        ---       ---
5       NO       --     -/ -/ -     ---        ---       ---
6       NO       --     -/ -/ -     ---        ---       ---
7       NO       --     -/ -/ -     ---        ---       ---
8       NO       --     -/ -/ -     ---        ---       ---
9       NO       --     -/ -/ -     ---        ---       ---


After the configuration of base station access service is complete, you can use the test meter to perform tests on the E1 port of the ONU and the upstream E1/STM-1 port of the TOPA board. If you have problems or errors during configuration, you can contact our supports team for assistant.



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