2.1 General Service Process Overview
Concept Analogy
A router is a device that searches for paths to transmit IP packets on the Internet. The router
functions as a post office. IP packets are to the router as mails to the post office. The core function
of a router is addressing and forwarding.
In a post office, a mail collection center collects all mails, and a mail query and distribution
center queries addresses of the mails and distributes these mails to their addresses. A mail
collection center, similar to the data plane on a router, collects mails. A mail query and
distribution center, similar to the control plane on the router, searches for paths and forwards
mails along the paths to various addresses.
Logical Architecture
A router consists of the data and control planes, which implements addressing and forwarding.
In addition, the router has a monitoring plane, which helps ensure stable addressing and
forwarding performance. The three planes provide the following functions:
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Data plane: Similar to a mail collection center, the data plane provides interfaces that send
and receive packets on a router, while processing the packets at a high speed and switching
data packets inside the router. The data plane encapsulates packets, decapsulates packets,
processes Ethernet, Multiprotocol Label Switching (MPLS), IPv4, and IPv6 packets,
implements quality of service (QoS), schedules packets, and provides various statistics.
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Control plane: Similar to the mail query and distribution center, the control plane is the
central nervous system on a router. It uses system buses to control system units and provide
various functions. These functions allow the router to calculate routes, generate LSPs, build
multicast, unicast, and MPLS forwarding tables, processes protocols and signalings,
configure the routes, maintain the route status, monitor the system status, and generate the
system status report.
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Monitoring plane: monitors the system environment and helps the data and control plane
operate stably and securely. The monitoring plane measures the power voltage, controls
the system power-on and power-off, monitors temperatures, and controls fan modules. In
addition, the monitoring plane isolates a fault if a unit fails to prevent the fault from affecting
other units on the router.
illustrates the logical architecture of a router.
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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