H3C S3600 Series User Manual

Operation Manual – QoS-QoS Profile
H3C S3600 Series Ethernet Switches-Release 1510 Chapter 1
QoS Configuration
1-6
I. Traffic evaluation and the token bucket
The token bucket can be considered as a container with a certain capacity to hold
tokens. The system puts tokens into the bucket at the set rate. When the token bucket
is full, the extra tokens will overflow and the number of tokens in the bucket stops
increasing.
需由此接口发送的包
继续发送
令牌桶
按规定的速率向桶内放置令牌
分类
丢弃
Packet to be sent on this interface
Continue to send
Token buc
Put tokens into the bucket a
ket
t the set rate
Classify
Drop
需由此接口发送的包
继续发送
令牌桶
按规定的速率向桶内放置令牌
分类
丢弃
Packet to be sent on this interface
Continue to send
需由此接口发送的包
继续发送
令牌桶
按规定的速率向桶内放置令牌
分类
丢弃
Packet sent via this interface
Continue to send
Token buc
Put tokens into the bucket a
ket
t the set rate
Classify
Drop
需由此接口发送的包
继续发送
令牌桶
按规定的速率向桶内放置令牌
分类
丢弃
Packet to be sent on this interface
Continue to send
需由此接口发送的包
继续发送
令牌桶
按规定的速率向桶内放置令牌
分类
丢弃
Packet to be sent on this interface
Continue to send
Token buc
Put tokens into the bucket a
ket
t the set rate
Classify
Drop
需由此接口发送的包
继续发送
令牌桶
按规定的速率向桶内放置令牌
分类
丢弃
Packet to be sent on this interface
Continue to send
需由此接口发送的包
继续发送
令牌桶
按规定的速率向桶内放置令牌
分类
丢弃
Packet sent via this interface
Continue to send
Token buc
Put tokens into the bucket a
ket
t the set rate
Classify
Drop
Figure 1-4 Evaluate the traffic with the token bucket
1) Evaluating the traffic with the token bucket
The evaluation for the traffic specification is based on whether the number of tokens in
the bucket can meet the need of packet forwarding. If the number of tokens in the
bucket is enough to forward the packets (generally, one token is associated with a 1-bit
forwarding authority), the traffic is conforming to the specification; otherwise, the traffic
is nonconforming or excess.
When the token bucket evaluates the traffic, its parameter configurations include:
z Average rate: The rate at which tokens are put into the bucket, namely, the
permitted average rate of the traffic. It is generally set to committed information
rate (CIR).
z Burst size: The capacity of the token bucket, namely, the maximum traffic size that
is permitted in each burst. It is generally set to committed burst size (CBS). The set
burst size must be greater than the maximum packet length.
One evaluation is performed on each arriving packet. In each evaluation, if the number
of tokens in the bucket is enough, the traffic is conforming to the specification and you
must take away some tokens whose number is corresponding to the packet forwarding
authority; if the number of tokens in the bucket is not enough, it means that too many
tokens have been used and the traffic is excess.
2) Complicated evaluation
You can set two token buckets in order to evaluate more complicated conditions and
implement more flexible regulation policies. For example, TP uses four parameters:

H3C S3600 Series Specifications

General

Brand	H3C
Model	S3600 Series
Category	Switch
Language	English