Example for Configuring the Multicast MAC Encapsulation Mode for G.8275.1 Packets to Achieve Network-wide Time Synchronization
Networking Requirements
G.8275.1 can be used as a time synchronization protocol to transmit time signals of the BITS server on the entire network so that network-wide time synchronization can be achieved for base stations.
On the network shown in Example for Configuring the Multicast MAC Encapsulation Mode for G.8275.1 Packets to Achieve Network-wide Time Synchronization, the transport network carries the wireless services between NodeBs, and all transport network nodes support G.8275.1. To ensure time synchronization between G.8275.1-capable base stations and transport network devices, you can configure G.8275.1 and time can be configured use network-wide T-BCs to transmit time information.
Interfaces 1 through 3 in this example represent GE 0/1/0, GE 0/1/1, and GE 0/1/2, respectively.
Configuration Roadmap
The configuration roadmap is as follows:
Connect PE1 and PE2 to BITS servers.
Configure PE1, PE2, Device1, and Device2 as T-BCs to implement network-wide time synchronization.
- Configure synchronous Ethernet to implement frequency synchronization for a higher synchronization precision.
- Enable performance monitoring on the passive interfaces of Device1 and Device2.
- To prevent reverse synchronization of clock signals, disable Interface 1 on PE1 and PE2 and Interface 2 on Device1 and Device2 from working in the slave state.
Configure devices to use the default multicast MAC encapsulation mode to transmit G.8275.1 packets.
Procedure
- Configure PE1 and PE2 to import BITS clock signals through their clock interfaces. The configuration details are not provided here.
- Configure PE1, PE2, Device1, and Device2 as T-BCs.
- Configure base stations to receive G.8275.1 packets from Device1 and Device2. The configuration details are not provided here.
- Verify the configuration.
After completing the configurations, run the display ptp all command to check the running status of G.8275.1. The following example uses the command output on Device1. The command output shows that the G.8275.1 interface GE 0/1/0 on Device1 is working in the Slave state, the grandmaster clock ID is 0a05d7fffe341500, and the parent clock ID is 0a05d7fffe341500. Device1 has synchronized with the master clock source.
[~Device1] display ptp all Device config info ------------------------------------------------------------------------------ PTP state :enabled Domain value :24 Slave only :- Device type :T-BC Set port state :- Local clock ID :0aa1c6fffe699700 Acl :no Virtual clock ID :no Acr :- Time lock success :yes Asymmetry measure :disable Passive measure :enable PTP profile :G.8275.1 V2.0 Send GM WTR :no BMC run info ------------------------------------------------------------------------------ Grand clock ID :0a05d7fffe341500 Receive number :GigabitEthernet0/1/0 Parent clock ID :0a05d7fffe341500 Parent portnumber :35585 Priority1 :128 Priority2 :128 Step removed :0 Clock accuracy :0xfe Clock class :6 Time Source :0xa0 UTC Offset :35 UTC Offset Valid :True Timescale :PTP Time traceable :True Leap :None Frequency traceable :True Offset scaled :0xffff Sync uncertain :True Port info Name State Delay-mech Ann-timeout Type Domain ------------------------------------------------------------------------------ GigabitEthernet0/1/0 slave delay 3 T-BC 24 Time Performance Statistics(ns): Slot X Card X Port X ------------------------------------------------------------------------------ Realtime(T2-T1) :1104 Pathdelay :0 Max(T2-T1) :1110 Min(T2-T1) :1100 Clock source info Clock Pri Pri2 Accuracy Class TimeSrc Signal Switch Direction In-Status ------------------------------------------------------------------------------ local 128 128 0xFE 248 0xa0 - - - - bits1/11 128 128 0x20 6 0x20 1pps off in/- normal bits1/12 128 128 0x20 6 0x20 1pps off in/- normal
Configuration Files
PE1 configuration file
# sysname PE1 # ptp enable ptp profile g-8275-1 enable ptp device-type t-bc # interface GigabitEthernet0/1/0 undo shutdown clock synchronization enable ptp enable # returnPE2 configuration file
# sysname PE2 # ptp enable ptp profile g-8275-1 enable ptp device-type t-bc # interface GigabitEthernet0/1/0 undo shutdown clock synchronization enable ptp enable # returnDevice1 configuration file
# sysname Device1 # ptp enable ptp profile g-8275-1 enable ptp device-type t-bc ptp passive-measure enable # interface GigabitEthernet0/1/0 undo shutdown ptp notslave disable clock synchronization enable clock priority 10 ptp enable # interface GigabitEthernet0/1/1 undo shutdown clock synchronization enable ptp enable # interface GigabitEthernet0/1/2 undo shutdown ptp notslave disable clock synchronization enable clock priority 20 ptp enable # return
Device2 configuration file
# sysname Device2 # ptp enable ptp profile g-8275-1 enable ptp device-type t-bc ptp passive-measure enable # interface GigabitEthernet0/1/0 undo shutdown ptp notslave disable clock synchronization enable clock priority 10 ptp enable # interface GigabitEthernet0/1/1 undo shutdown clock synchronization enable ptp enable # interface GigabitEthernet0/1/2 undo shutdown ptp notslave disable clock synchronization enable clock priority 20 ptp enable # return