Qtech QSW-3200-28FC Руководство пользователя онлайн [66/136] 481610
Макгруп McGrp.ru
Задайте вопрос
Зарегистрироваться

Qtech QSW-3200-28FC Руководство пользователя онлайн [66/136] 481610

Qtech QSW-3200-28T Руководство пользователя онлайн [66/136] 481609
+7(495) 797-3311www.qtech.ru
Москва, Новозаводская ул., 18, стр. 1
55
7. Redirection
User can re-specify the packet transmission interface based on the need of its own QoS
strategies.
8. Priority mark
Ethernet switch can provide priority mark service for specified packet, which includes: TOS,
DSCP, 802.1p. These priority marks can adapt different QoS model and can be defined in
these different models.
9. Choose interface outputting queue for packet
Ethernet switch can choose corresponding outputting queue for specified packets.
10. Queue scheduler
It adopts queue scheduler to solve the problem of resource contention of many packets when
network congestion. There are three queue scheduler matchings: Strict-Priority Queue (PQ),
Weighted Round Robin (WRR) and WRR with maximum delay.
(1)PQ
PQ (Priority Queueing) is designed for key service application. Key service possesses an
important feature, that is, require the precesent service to reduce the response delay when
network congestion. Priority queue divides all packets into 4 levels, that is, superior priority,
middle priority, normal priority and inferior priority (3, 2, 1, 0), and their priority levels reduce in
turn.
When queue schedulerimg, PQ precedently transmits the packets in superior priority according
to the priority level. Transmit packet in inferior priority when the superior one is empty. Put the
key service in the superior one, and non-key service (such as email)in inferior one to
guarantee the packets in superior group can be first transmitted and non-key service can be
transmitted in the spare time.
The shortage of PQ is: when there is network congestion, there are more packets in superior
group for a long time, the packets in inferior priority will wait longer.
(2)WRR
WRR queue scheduler divides a port into 4 or 8 outputting queues (QSW-3200 has 4 queues,
that is, 3, 2, 1, 0) and each scheduler is in turn to guarantee the service time for each queue.
WRR can configure a weighted value (that is, w3, w2, w1, w0 in turn) which means the
percentage of obtaining the resources. For example: There is a port of 100M. Configure its
WRR queue scheduler value to be 50, 30, 10, 10 (corresponding w3, w2, w1, w0 in turn) to
guarantee the inferior priority queue to gain at least 10Mbit/s bandwidth, to avoid the shartage
of PQ queue scheduler in which packets may not gain the service.
WRR possesses another advantage. The scheduler of many queues is in turn, but the time for
service is not fixed——if some queue is free, it will change to the next queue scheduler to
make full use of bandwidth resources.
(3) WRR with maximum delay
Compared with WRR, WRR with maximum delay can guarantee the maximum time from
packets entering superior queue to leaving it will not beyond the configured maximum delay.
11. The cos-map relationship of hardware priority queue and priority of IEEE802.1p protocol
System will map between 802.1p protocol priority of packet and hardware queue priority. For
each packet, system will map it to specified hardware queue priority according to 802.1p
protocol priority of packet.
12. Flow mirror
Flow mirror means coping specified data packet to monitor interface to detect network and
exclude failure.
13. Statistics based on flow
Statistics based on flow can statistic and analyse the packets customer interested in.

Содержание

Похожие устройства

Скачать