NE40 HQoS VRP5.30使用注意事项

层次化QOS技术，即Hierarchical QoS技术，是一项解决在Diffserv模型下多用户多业务的带宽保证技术。第一级调度支持给每个用户配置带宽，实现了对每个用户总带宽的控制，保证了在拥塞发生时每个用户的带宽能得到保证；第二级调度（包含8种优先级队列：BE、AF1－AF4、EF、Cs6、Cs7）支持PQ、CBPQ、CBFQ三种方式。

但是注意HQOS只在出接口方向启作用，并且不能和流量监管Car同时使用，HQOS的Bandwith配置和CAR一样具有限定接口速率的功能。

另外注意HQOS配置时不需要时能Commit Traffic policy就能立刻生效。

 

如果在出接口同时使用CAR和HQoS，会导致有部分报文从入口进但是却不能通过出口转发，同时查看HQoS的使用情况却没有发现有报文被HQos丢弃。

当NE40如下方式配置HQoS时会出现问题：

使用版本NE40&NE80 V300R002C01B533

acl number 10001                                                                

 rule ip source 10.72.0.2 0.0.0.0 destination 10.18.0.6 0.0.0.0

traffic classifier ef                                                          

 if-match acl 10001                                      

traffic behavior car                                                            

 car cir 6000 cbs 12288 green pass yellow remark red discard                   

traffic behavior ef                                                            

 remark dscp ef        

traffic policy car                                                              

 classifier car behavior car precedence 0                                      

traffic policy ef                                                              

 classifier ef behavior ef precedence 0    

                                                                         

interface Ethernet2/0/2                                                        

 description TO-NE40-A                                                         

 undo shutdown                                                                  

 ip address 10.3.1.6 255.255.255.252                                           

 traffic-policy car outbound                   //配置流量监管，目的是限制带宽为6M                                        

 hqos policy cbpq bandwidth 6000              //配置HQoS带宽，目的是限制带宽为6M 

 hqos queue ef cir 1200 remark                                                  

#                                                                              

interface Ethernet2/0/3                                                         

 description TO-AR46-C                                                         

 undo shutdown                                                                 

 ip address 10.50.2.5 255.255.255.252                                           

 traffic-policy ef inbound                                                       

# 

 

通过构造1M的EF报文和7M的BE流量报文测试，发现NE40对1M的EF流量没有保障，仍然是丢弃40%左右，查看入出接口QoS统计如下：

[NE40-C]disp qos policy ef in                                                  

Classifier in Policy ef :                                                      

  Classifier ef Behavior ef Slot 2 :                                           

   The number of Policy hits : 2395                                            

                                                                               

[NE40-C]disp qos queue statistics Ethernet 2/0/2 ef                            

Ethernet2/0/2 statistics:                                                      

  Forward bits            : 16744064                                           

  Forward pacekts         : 2036                                                

  Remark  bits            : 0                                                  

  Remark  packets         : 0                                                  

  Drop    bits            : 0                                                   

  Drop    packets         : 0                                                  

  Forward bits   rate     : 123591 bits/sec                                    

  Forward packet rate     : 15 packet/sec                                       

 

发现出接口没有报文丢弃，但是明显有部分报文没有走入HQoS流程。

删除出接口的流量监管配置后，HQoS立刻正常起作用。