the MPU delivers signaling to the data plane so that they can be identified by the data
plane.
–
MPU-to-board signal flow: used to update entries in forwarding tables. After the MPU
delivers parsed data to a board, the board uses the data to forward packets on the data
plane.
In the following example, routing calculation is used. A packet arrives at an interface of a
board. The network processor (NP) on the board identifies the packet that needs to be sent
to the MPU. The NP sends the packet to the MPU. The MPU calculates the packet and
delivers the destination IP address and the next-hop IP address to the routing table on the
NP. The data plane forwards the packet to the next-hop address over a route to the
destination IP address.
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Operation and maintenance signal flow: Operation data includes configuration, debugging,
and query data. Maintenance data includes system-generating data, such as logs and alarms.
–
Board-to-MPU signal flow: contains maintenance signals. The system management and
control unit uses the system buses to collect maintenance information, such as logs and
alarms that are generated by modules and saves the information in an information center.
The maintenance data helps query and maintain the device.
For example, when a user wants to query active alarms, the user runs the
display alarm
active
command. The control plane parses this command and instructs the information
center to display all collected active alarms.
–
MPU-to-board signal flow: contains operation signals. The control plane provides
software interfaces to communicate with other devices, communication interfaces to
communicate with host software, and LAN switch interfaces to communicate with other
boards and modules. These interfaces form a logical network. Operation commands are
configured on the control plane. The control plane then sorts information based on types
and priorities and sends the information through interfaces along various channels to
various modules.
For example, a user runs the
power off slot 1
command to power off a board in slot 1.
The control plane parses the command and delivers the command through an outband
interface to the board in slot 1.
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Clock signal flow: contains synchronization Ethernet or 1588v2 (also called IEEE Standard
for a Precision Clock Synchronization Protocol for Networked Measurement and Control
Systems) signals.
–
Board-to-MPU signal flow: used to obtain clock signals. An uplink board obtains clock
frequency signals from packets and sends them to the system clock unit on an MPU.
The system clock unit then selects a clock source.
–
MPU-to-board signal flow: used to restore the system clock frequency and time. After
the MPU selects a clock source, it restores the synchronous system clock and delivers
it to all boards so that a device forwards packets all carrying the synchronous signals to
downstream devices through outbound interfaces.
Reliability
Both the MPUs and clocks are working in 1:1 redundancy mode. The master and slave MPUs
communicate and monitor each other's status. If the master MPU fails, the slave MPU
automatically takes over packets and becomes the new master MPU, which improves device
reliability.
HUAWEI CX600-8/16/X3/X8/X16 Metro Service Platform
Hardware Description
2 Product Signal Flow Overview
Issue 03 (2013-11-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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