Configuring CU-106
Usage Scenario
On the network shown in Figure 1, the BITS interface that
functions as the T-GM obtains high-accuracy time information from
a global positioning system (GPS), encapsulates the information into
a CU-106 packet, and sends the packet to the bearer network. A bearer
network device that functions as the T-BC transparently transmits
the time information to all devices on the bearer network. BCs send
high-accuracy time information carried in the CU-106 packet to wireless
access devices, such as a NodeB and a radio network controller (RNC).
- Configuring a BITS Source as the T-GM
- You can configure a building integrated timing supply system (BITS) source as the telecom grandmaster (T-GM). The T-GM then provides time signals for its connected transport network T-BCs over Ethernet clock interfaces, allowing the T-BCs to achieve time synchronization with the T-GM.
- Configuring Clock Source Attributes for BMC Selection
- After multiple T-BCs are configured with the input of BITS signals, clock source attributes for BMC selection can be configured on the T-BCs to allow the T-BCs to participate in BMC selection. The local clocks of T-BCs can also be configured to participate in BMC selection. BMCA can be used to dynamically determine the T-GM. The T-GM provides time signals for the entire CU-106 network. T-BCs use CU-106 to obtain time synchronization information from the T-GM.
- Globally Enabling CU-106
- To ensure CU-106 for time synchronization, enable CU-106 globally in the system view and configure basic information on a device, such as the device type (T-BC or T-TC), domain value, and virtual clock ID.
- (Optional) Configuring the Time Synchronization Alarm Function
- After the time synchronization alarm function is configured to monitor time synchronization status information, the alarm information will be reported to the NMS for further troubleshooting and maintenance.
- Configuring CU-106 on an Interface
- After enabling CU-106 in the system view, you need to enable CU-106 in the interface view.
- Configuring Time Attributes for CU-106 Packets
- This section describes how to configure time attributes for CU-106 packets. T-BCs exchange Announce, Sync, and Delay or Pdelay packets to send time information and maintain CU-106 connections. You can set the interval at which a CU-106 interface sends Announce, Sync, and Delay or Pdelay packets and the maximum number of Announce packet timeouts. Using the default time attribute values is recommended.
- Configuring Encapsulation Modes for CU-106 Packets
- You can configure destination MAC addresses of packets according to the actual networking.
- Verifying the Configuration of CU-106
- After configuring the CU-106 function, verify the configuration.