Huawei Technologies Co. Ltd EM820W 사용자 설명서
support the scheduling modes of priority queuing (PQ), deficit round robin (DRR), weighted
round robin (WRR), PQ+DRR, and PQ+WRR. The AR150&200&1200 series routers do not
support the DRR mode. WAN-side interfaces support the scheduling modes of PQ, WFQ, PQ
+WFQ, and class-based WFQ (CBQ). Each scheduling algorithm schedules specific types of
traffic, and affects bandwidth allocation, delay, and jitter.
round robin (WRR), PQ+DRR, and PQ+WRR. The AR150&200&1200 series routers do not
support the DRR mode. WAN-side interfaces support the scheduling modes of PQ, WFQ, PQ
+WFQ, and class-based WFQ (CBQ). Each scheduling algorithm schedules specific types of
traffic, and affects bandwidth allocation, delay, and jitter.
Congestion Avoidance
Congestion avoidance is a flow control mechanism. A system configured with congestion
avoidance monitors network resource usage such as queues and memory buffers. When
congestion occurs or aggravates, the system discards packets.
avoidance monitors network resource usage such as queues and memory buffers. When
congestion occurs or aggravates, the system discards packets.
The ARs support tail drop and WRED.
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Tail drop
When the queue length reaches the upper limit, the excess packets (buffered at the queue
tail) are discarded.
When the queue length reaches the upper limit, the excess packets (buffered at the queue
tail) are discarded.
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WRED
WRED sets the upper and lower drop thresholds and the maximum drop probability for
each queue. When the queue length is smaller than the lower threshold, no packets are
discarded. When the length of the queue exceeds the upper threshold, all packets are
discarded. When the queue length is between the lower threshold and the upper threshold,
incoming packets are discarded randomly. The drop probability cannot be greater than the
maximum drop probability.
The ARs use the WRED based on queue profiles or traffic policies.
WRED sets the upper and lower drop thresholds and the maximum drop probability for
each queue. When the queue length is smaller than the lower threshold, no packets are
discarded. When the length of the queue exceeds the upper threshold, all packets are
discarded. When the queue length is between the lower threshold and the upper threshold,
incoming packets are discarded randomly. The drop probability cannot be greater than the
maximum drop probability.
The ARs use the WRED based on queue profiles or traffic policies.
For details about QoS features, see Feature Description - QoS.
3.2.6 WLAN
NOTE
Only AR1220W and AR1220VW support WLAN.
A wireless local area network (WLAN) connects two or more computers or devices and enables
the devices to communicate by using the wireless telecommunication technology. WLAN uses
the wireless technology to implement fast Ethernet access. The primary advantage of WLAN is
that terminals, such as computers, can access a network through a wireless medium rather than
a physical cable. This facilitates network construction and allows users to move around without
interrupting communication. WLAN is more flexible than traditional wired access.
the devices to communicate by using the wireless telecommunication technology. WLAN uses
the wireless technology to implement fast Ethernet access. The primary advantage of WLAN is
that terminals, such as computers, can access a network through a wireless medium rather than
a physical cable. This facilitates network construction and allows users to move around without
interrupting communication. WLAN is more flexible than traditional wired access.
WLAN is widely used in public areas such as on campuses, business centers, and airports. The
WLAN uses cables at the backbone layer, and users access the WLAN through one or more
wireless access points (WAPs) using radio waves. The transmission distance of a WAP is tens
of meters.
WLAN uses cables at the backbone layer, and users access the WLAN through one or more
wireless access points (WAPs) using radio waves. The transmission distance of a WAP is tens
of meters.
IEEE 802.11 is widely used by WLANs. The AR functions as fat APs to provide the following
WLAN functions:
WLAN functions:
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WLAN user management
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Dot1X access authentication
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MAC address authentication
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Pre-share-key (PSK) authentication
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EAPOL-Key negotiation
Huawei AR G3 Series Enterprise Routers
Product Description
Product Description
3 Product Characteristics
Issue 02 (2012-04-20)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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