HP 5500 Ei 5500 Si Switch Series Configuration Guide

 38 
Figure 10 GTS 
 
 
For example, in Figure 11, Device B performs traffic policing on packets from Device A and drops packets 
exceeding the limit. To avoid packet loss, you can pe rform traffic shaping on the outgoing interface of 
Device A so packets exceeding the limit are cached in Device A. Once resources are released, traffic 
shaping takes out the cached packets and sends them out.  
Figure 11  GTS application 
 
 
Line rate 
Line rate supports rate-limiting the outbound traffic.  
The line...

 39 
Figure 12 Line rate implementation 
 
 
The token bucket mechanism limits traffic rate when accommodating bursts. It allows bursty traffic to be 
transmitted if enough tokens are available. If toke ns are scarce, packets cannot be transmitted until 
efficient tokens are generated in the token bucket. It restricts the traffic rate to the rate for generating 
tokens. 
Line rate can only limit traffic rate  on a physical interface, and traffic policing can limit the rate of a flow 
on an interface. To...

 40 
Step Command Remarks 
6.  Configure a traffic policing 
action.  car cir 
committed-information-rate  [ cbs 
committed-burst-size  [ ebs 
excess-burst-size  ] ] [ pir 
peak-information-rate ] [ green  action  ] 
[ yellow  action  ] [ red action  ]   N/A  
7.
  Return to system view. 
quit  N/A 
8.  Create a policy and enter 
policy view.  qos policy
 policy-name   N/A 
9.  Associate the class with the 
traffic behavior in the QoS 
policy.  classifier 
tcl-name behavior 
behavior-name   N/A 
10....

 41 
Step Command Remarks 
1.  Enter system view. 
system-view  N/A 
2.  Enter interface view 
or port group view. 
• Enter interface view: 
interface  interface-type 
interface-number 
•  Enter port group view: 
port-group manual 
port-group-name  Use either command. 
Settings in interface view take effect on the 
current interface. Settings in port group view 
take effect on all ports in the port group. 
3.
  Configure the line 
rate for the interface 
or port group.  qos lr outbound cir...

 42 
•  Limit the outgoing HTTP traffic (traffic accessing the Internet) rate of GigabitEthernet 1/0/2 to 1024 
kbps, and drop the excess traffic.  
Figure 13  Network diagram 
 
 
Configuration procedures 
1. Configure Device A: 
# Configure ACL 2001 and ACL 2002 to match traffic from Server and Host A, respectively.  
 system-view 
[DeviceA] acl number 2001 
[DeviceA-acl-basic-2001] rule permit source 1.1.1.1 0 
[DeviceA-acl-basic-2001] quit 
[DeviceA] acl number 2002 
[DeviceA-acl-basic-2002] rule...

 43 
[DeviceA-qospolicy-car] classifier server behavior server 
[DeviceA-qospolicy-car] classifier host behavior host 
[DeviceA-qospolicy-car] quit 
# Apply QoS policy car to the incoming traffic of port GigabitEthernet 1/0/1.  
[DeviceA] interface GigabitEthernet 1/0/1 
[DeviceA-GigabitEthernet1/0/1] qos apply policy car inbound 
2. Configure Device B: 
# Configure advanced ACL 3001 to match HTTP traffic.  
 system-view 
[DeviceB] acl number 3001 
[DeviceB-acl-adv-3001] rule permit tcp destination-port...

 44 
Configuring congestion management 
Both bridge mode (Layer 2) and route mode (Layer 3) Ethernet ports support the congestion management 
function. The term interface i n thi s  chapter  c ol le ctively refers  to  these  t ypes  of  por ts. You  c an use  the  port 
link-mode  command to set an Ethernet port to operate in bridge or route mode (see  Layer 2—LAN 
Switching Configuration Guide ). 
The 5500 SI Switch Series does not support Layer 3 Ethernet ports.  
Overview 
Network congestion degrades...

 45 
SP queuing 
SP queuing is designed for mission-critical applications that require preferential service to reduce the 
response delay when congestion occurs. 
Figure 15  SP queuing 
 
 
In Figure 15 , SP queuing classifies eight queues on a port into eight classes, numbered 7 to 0 in 
descending priority order. 
SP queuing schedules the eight queues in the descendi ng order of priority. SP queuing sends packets in 
the queue with the highest priority first. When the queue with the highest priority is...

 46 
Figure 16 WRR queuing 
 
 
Assume a port provides eight output queues. WRR assigns each queue a weight value (represented by 
w7, w6, w5, w4, w3, w2, w1, or w0) to decide the proportion of resources assigned to the queue.  
•  T h e  55 0 0  S I  sw i t c h  s u p p o r t s  b y t e - c o u n t  w e i g h t,  w h i c h  d e t e r m i n e s  t h e  w e i g h t  b y  t h e  n u m b e r  o f  b y t e s  
scheduled in a cycle. 
•   T h e  55 0 0  E I  s w i t c h  s u p p o r t s  b y t e - c o u n t  w...

 47 
WFQ queuing 
Figure 17 WFQ queuing 
 
 
WFQ is similar to WRR. You can use WFQ as an alternative to WRR.  
Compared with WRR, WFQ can work with the minimum guaranteed bandwidth as follows: 
•  By setting the minimum guaranteed bandwidth, you can make sure that each WFQ queue is 
assured of certain bandwidth. 
•   The assignable bandwidth is allocated based on the priority of each queue (assignable bandwidth 
= total bandwidth – the sum of minimum guaranteed bandwidth of each queue).  
For example,...