Overview Of Ethernet Clock Syntonization; Ethernet Clock Syntonization Features Supported By The S9300 - Huawei Quidway S9300 Configuration Manual

Quidway S9300 Terabit Routing Switch
Configuration Guide - Device Management

11.1 Overview of Ethernet Clock Syntonization

Compared with the Global Positioning System (GPS), the Ethernet Syntonization function
synchronizes the clock frequency on the Ethernet at lower costs.
Concept of Clock Syntonization
On the data communication network, the sender needs to place the pulse signal in a specific time
slot, and the receiver needs to extract the pulse signal from the time slot. Therefore, to ensure
normal communication between the sender and the receiver, you must ensure clock
synchronization between them. This function is implemented by the clock.
Clock syntonization is used to keep the clock frequency difference among the network elements
on the digital network within a specific error range. If the clock frequency difference is out of
the allowed range, error codes and jitter may occur. This degrades the transmission performance.
Implementation of Ethernet Clock Syntonization
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Advantages of Ethernet Clock Syntonization
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11.2 Ethernet Clock Syntonization Features Supported by
the S9300
This section describes the hardware of the S9300 required for implementing Ethernet clock
syntonization, and the clock sources and clock source selection modes supported by the
S9300.
Clock Signal Transmission
The S9300 can transmit clock signals on the Ethernet or synchronous digital hierarchy (SDH)
network.
Issue 03 (2011-12-29)
The GPS provides an accurate clock.
A device supporting Ethernet clock syntonization recovers clock signals from lines or
receives clock signals through BITS interfaces, and then transmits clock signals to
downstream devices. Then the clock frequency is synchronized through the Ethernet.
Costs of construction and security guarantee of the GPS are high, whereas costs of the
Ethernet clock syntonization technology are much lower.
The Ethernet clock syntonization technology can be applied to existing Ethernet networks
so that these networks do not need to depend on the GPS.
NOTE
To use the Ethernet clock synchronization features, you must install the CKM-clock board and G24CEAS
on the S9300.
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