Huawei CR-NETB User manual

Quidway® NetEngine 80 Core Router Switching Network Board
Copyright ©2007 Huawei Technologies Co., Ltd. All Rights Reserved.
http://www.huawei.com/products/datacomm/ 1
Quidway® NetEngine 80 Core Router
Switching Network Board
Overview
The Switching Network Board (NETB) of the Quidway®NetEngine 80 core router (abbreviated to
NE80) not only realizes fast switching of data packets of fixed length on ports, but also provides
system level-3 synchronous clock.
The NE80 has 20 slots, of which two are for NETBs. One or two NETBs are required for each NE80.
Two NETBs are recommended to implement redundancy backup to improve the reliability of the
system.
CR-NETB
The NETB realizes switching network functions.
zAdopt the switching mode of dynamic output buffer sharing.
zRealize non-blocking and self-routing data switching.
zProvide 16 input and output ports, achieving a total capacity of 128 Gbps.
zHave hardware flow control and back-pressure mechanism.
zProvide a temperature sensor for ambient temperature detection, collection, reporting and
alarming of the network board.
The NETB of the NE80 adopts a Virtual Output Queuing (VOQ) design to eliminate head of line
(HOL) blocking: setting output queues on the Line Processing Units(LPU) uplink to implement
shared buffer, and deploying a greater Buffer on the LPU downlink to receive data from the
switching network.
The NETB also provides level-3 clock.

Quidway® NetEngine 80 Core Router Switching Network Board
Copyright ©2007 Huawei Technologies Co., Ltd. All Rights Reserved.
http://www.huawei.com/products/datacomm/ 2
zProvide highly precise and reliable SDH line interface clock signals (38.88 MHz) to interface
boards.
zHave four working modes: fast tracking, normal (tracking), hold and free-run.
zHave rough tune and fine tune function, realizing on-site frequency adjustment.
zEnable synchronization performance detection, alarming and control.
zHave two synchronous link input interfaces, realizing automatic switchover without causing
phase variation.
zCommunicate with the MPU through active and standby HDLC links, to be monitored,
configured and managed by the MPU.
Specifications
The NETB has four external interfaces: two external timing source input interfaces and two internal
timing source output interfaces.
Module
name Interface name Interface type Description
External timing source
input interface Quantity: 2, SMB interfaces
Timing source can be acquired
from BITS. Interfaces can be set
to 2048 Kbps or 2048 KHz.
CR-NETB
Internal timing source
output interface Quantity: 2, SMB interfaces
Provide reference clock to
downstream equipment.
Interfaces can be set to 2048
Kbps or 2048 KHz.