3Com Router User Manual
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Configuring Congestion Management687
lengths of various queues, and the number of bytes that may be continuously
transmitted by polling of every queue.
The priority queue may be configured according to the following methods:
1Configure the priority queue according to the network layer protocol
Based on packet length, TCP/UDP port number, whether or not matching ACL,
you can classify data packets, so that they can enter the queues with different
priority.
Perform the following configurations in system view.
Ta b l e 721 Configure the Priority Queue According to the Network Layer Protocol
By default, no priority queue is established.
Among them, pql-index is the group number of the priority queue, and
protocol-name is the protocol name, the current value may be IP.
With protocol-name as IP, value of queue-option is listed in the following table:
Ta b l e 722 Values of Queue-Option with Protocol as IP
2Configure the priority-list queuing according to the interface
The data packets can be classified according the different types of interfaces into
which the data packets are input, and be input into different priority queues.
Please perform the following configurations in the system view
Ta b l e 723 Configure the Priority-List Queuing According to the Interface
OperationCommand
Configure the priority queue according to
the network layer protocolqos pql pql-index protocol
protocol-name queue-option queue {
top | middle | normal | bottom }
Delete the classification policy in the
priority queueundo qos pql pql-index protocol
protocol-name queue-option queue {
top | middle | normal | bottom }
queue-optionMeaning
EmptyAll IP packets can be processed into queue
acl acl-number (1∼199)All IP packet fragments can be processed into
priority queue
fragmentsIP packets defined by theacl-number (normal) can
be processed into priority queue
greater-than bytes (0∼65535)IP packet with a length less than a certain value can
be processed into queue
less-than bytes (0∼65535)IP packet with a length greater than a certain value
can be processed into queue
tcp port (0∼6553)With the source or destination TCP port of IP packet
being the specified port, the packet can be
processed into queue.
udp port (0∼65535)With the source or destination UDP port of IP
packet being the specified port, the packet can be
processed into priority queue.
OperationCommand
Configure the priority-list queuing
according to the interfaceqos pql pql-index inbound-interface
interface-type interface-number
queue { top | middle | normal |
bottom }
688CHAPTER 49: CONGESTION MANAGEMENT
By default, no priority queue is established.
3Configure the default priority-list queuing.
The data packets that are not matched with any policy in the priority queue (both
protocol type and interface type are not matched) will be allocated to the default
priority queue.
Please perform the following configurations in the system view.
Ta b l e 724 Configure the Default Priority-List Queuing
By default, no default priority queue is established.
Multiple policies may be defined for the group of the priority queues, which is
then applied to an interface. When the data packet arrives at the interface, the
data packet is matched by the system according to the configured policy. The data
packet is inputted into the specified queue if it matches with the policy. If the data
packet does not match with any policy, it is inputted into the default priority
queue. If the default priority queue is not configured, the default priority queue
group is 16 with the priority level as normal.
Applying the priority-list queuing group to the interface
To put the priority queue into function, the configured priority queue group must
be applied to the specific interface. Every interface can only use one priority queue
group, but one priority queue can be applied to multiple interfaces. Multiple
different priority queues group can be established to apply to different interfaces.
Perform the following configurations in the interface view.
Ta b l e 725 Apply the Priority-List Queuing Group to the Interface
By default, the interface utilizes the FIFO queue.
Specifying the queue length of the priority-list queuing
The queue length of each priority queue (the maximum number of the data
packets that may be accommodated) can be specified.
Perform the following configurations in the system view.
Ta b l e 726 Configure the Queue Length of the Priority-List Queuing
Delete the classification policy in the
priority queueundo qos pql pql-index
inbound-interface interface-type
interface-number
OperationCommand
Configure the default priority-list queuingqos pql pql-index default-queue { top
| middle | normal | bottom }
Recover the default priority of the priority
queueundo qos pql pql-index default-queue
OperationCommand
Apply the priority-list queuing group on
the interfaceqos pq pql pql-index
Cancel applying the priority-list queuing
group on the interfaceundo qos pq
OperationCommand
Configuring Congestion Management689
queue-length is the queues lengths of the 4 priority levels. They range 1 to 1024
packets.
The default length of each priority queue is shown in the following table:
Ta b l e 727 Default Length Value of the Priority Queue
Displaying and debugging the priority queue
Ta b l e 728 Display and Debug the Priority Queue
Configuring Custom
Queuing (CQ)Custom queuing configuration includes:
■Configuring custom-list queuing
■Applying the custom-list queuing group to the interface
■Configuring the queue length of the custom-list queuing
■Configuring the number of the continuously transmitted bytes of the custom
queue
■Displaying and debugging the custom-list queue
Configuring custom-list queuing
Custom queuing includes up to 16 groups (the value range of cql-index is 1 to 16),
each of which specifies which types of data packets are input to each queue, the
lengths of various queues, and the number of bytes that can be continuously
transmitted by polling every queue. Every time the packets are transmitted, the
packets in queues 1 to 16 are transmitted sequentially, and the number of the
transmitted bytes for every transmission is not less than the number of the
specified bytes in this queue, until this queue is empty.
Multiple custom queues can be configured, and the data packet will be matched
by the system according to the specified sequence order in the policy list. If it is
found that the data packet is matched with a policy, the entire searching process
comes to an end.
The custom queue may be configured according to the following methods:
Configure the queue length of the
priority-list queuingqos pql pql-index queue { top |
middle | normal | bottom }
queue-length queue-length
Recover the default value of the priority
queue lengthundo qos pql pql-index queue { top |
middle | normal | bottom }
queue-length
QueueLength
top20
middle40
normal60
bottom80
OperationCommand
Display the priority queue configuration
conditions and statistic information of the
interfacedisplay qos pql [ interface type
number ]
Display the content of the priority listdisplay qos pql
690CHAPTER 49: CONGESTION MANAGEMENT Configure the custom queue according to the network layer protocol The data packets can be classified according to different protocol types, and be input to different custom queues. Perform the following configurations in the system view. Ta b l e 729 Configure the Custom Queue According to the Network Layer Protocol Among them, cql-index is the group number of the custom queue; queue-number is the queue number with the value ranging 0 to 16. protocol-name may be ip, and the value range of queue-option is the same as that of the priority queue. Configure custom-list queuing according to the interface The data packets can be classified according to different types of the router interfaces into which the data packets are inputted, and be inputted into different custom queues. Perform the following configurations in the system view. Ta b l e 730 Configure the Custom-Lst Queuing According to the Interface Configure the default custom-list queuing The data packets that are not matched with any policy in the custom queue will be allocated to the default custom queue. Perform the following configurations in the system view. Ta b l e 731 Configure the Default Custom-List Queuing Multiple policies can be defined for the group of the custom-list queues, which is then applied to an interface. When the data packet arrives at the interface, the data packet is matched by the system according to the configured policy, and the data packet is input to the specified custom queue if it matches with the policy. If the data packet does not match with any policy, it is input to the default queue. If the default custom-list queue is not configured, the priority level is normal. Operation Command Configure the custom queue according to the network layer protocolqos cql cql-index protocol protocol-name queue-option queue queue-number Delete the classification policy in the custom queueundo qos cql cql-index protocol protocol-name queue-option queue queue-number OperationCommand Configure the custom-list queuing according to the interfaceqos cql cql-index inbound-interface interface-type interface-number queue queue-number Delete the policy in the custom queueundo qos cql cql-index inbound-interface interface-type interface-number OperationCommand Configure the default custom-list queuingqos cql pql-index default-queue queue-number Recover the default queue number of the custom-list queueundo qos cql pql-index default-queue
Configuring Congestion Management691 Applying the custom-list queuing group to the interface To put the custom-list queue into operation, the configured custom-list queue must be applied to the specific interface. Every interface can only use one custom queue, but one custom queue can be applied to multiple interfaces. Multiple different custom queues may be established to apply to different interfaces. Perform the following configurations in the interface view. Ta b l e 732 Apply Custom-List Queuing to the Interface By default, the interface uses the FIFO queue. Configuring the queue length of the custom-list queuing The queue length of each priority queue (the maximum number of the data packets that can be accommodated) can be specified. Perform the following configurations in the system view. Ta b l e 733 Configure the Queue Length of the Custom-List Queuing By default, the length of the custom-list queue is 20, and the range of the value is 1 to 1024. Configuring the number of the continuously transmitted bytes of the custom queue The number of bytes of the continuously transmitted packets (the total number of the accommodated bytes) may be specified for each custom queue. Perform the following configurations in the system view. Ta b l e 734 Configure the Number of the Continuously Transmitted Bytes of the Custom Queuing By default, the number of bytes transmitted by respective queues in every polling is 1500, and the range of the value is 1 to 16777215. OperationCommand Apply the custom-list queuing group on the interfaceqos cq cql cql-index Cancel the application of the custom-list queuing group on the interfaceundo qos cq OperationCommand Configure the queue length of the custom-list queuingqos cql cql-index queue queue-number queue-length queue-length Recover the default value of the custom-list queue lengthundo qos cql cql-index queue queue-number queue-length OperationCommand Configure the number of the continuously transmitted bytes of the custom queuingqos cql cql-index queue queue-number serving byte-count Recover the default value of the continuously transmitted bytes of the custom queuingundo qos cql cql-index queue queue-number serving
692CHAPTER 49: CONGESTION MANAGEMENT byte-count: When the router dispatches the user queue of CQ, it continuously extracts and sends the data packets from this queue, until the number of the transmitted bytes is not less than the byte-count value configured for this queue or the queue is empty, the next user queue of CQ is to be transmitted. Therefore, the byte-count value will affect the proportional relationship of the occupied interface bandwidth between various user queues of CQ, and determine how long the router will dispatch the next queue of CQ. If the byte-count value is too small, the router will go to the next queue after at least one data packet is transmitted, and the bandwidths allocated to various queues may be far from the expected result. If the byte-count is too large, it may cause the too long delay of the switching between the queues. Displaying and debugging the custom-list queue Ta b l e 735 Display and Debug the Custom-List Queue Configuring WFQTo configure weighted fair queuing, perform the following configurations in the interface view.: ■Configuring Weighted fair queuing ■Displaying and debugging the weighted fair queue Configuring Weighted fair queuing Ta b l e 736 Configure Weighted Fair Queuing By default, the adopted congestion management policy is FIFO. By default, max-queue-length is 64 packets. discard-threshold can range from 1 to 1024 packets. total-queue-number is 256 dynamic queues by default. It can be the following values: 16, 32, 64, 128, 256, 512, 1024, 2048 and 4096. Displaying and debugging the weighted fair queue Ta b l e 737 Display and Debug the Weighted Fair Queue OperationCommand Display the custom queue configuration conditions and statistic information of the interfacedisplay qos cql [ interface type number ] Display the content of the custom list.display qos cql OperationCommand Configure the weighted fair queuingqos wfq [ queue-length max-queue-length [ queue-number total-queue-number ] ] Recover the default queue congestion management policy of the interfaceundo qos wfq OperationCommand Display the custom-list queue configuration conditions and statistic information of the interfacedisplay qos wfq [ interface type number ]
Congestion Management Configuration Examples693 Congestion Management Configuration Examples PQ Configuration Example 1Define the access control table, and allow the packets from 10.10.0.0 network segment to pass through. [Router]acl 1 [Router-acl-1]rule permit source 10.10.0.0 2Define one policy for the group 1 of the priority queue: The IP packet that meets the acl-number value being 1 is inputted into the queue with the priority level of top. [Router] qos pql 1 protocol ip acl 1 queue top 3Set the length of the group 1 top queue of the priority queue to 10, while the lengths of other queues utilize the default values. [Router] qos pql 1 queue top queue-length 10 4Apply the priority queue 1 to Serial 0. [Router-Serial0] qos pq pql 1 5One policy is defined for the group 2 of the priority queue, so that all the IP packets from the Serial 1 interface are inputted into the queue with the priority level of middle. [Router] qos pql 2 inbound-interface serial 0 queue middle 6Apply the priority queue 2 to Serial 1. [Router-Serial0] qos pq pql 2 CQ Configuration Example Establish two parallel Tunnel channels (encapsulated GRE) that correspond to the same physical line in WAN. The proportional allocation of the physical line bandwidth should be implemented for the services on both tunnels.
694CHAPTER 49: CONGESTION MANAGEMENT Figure 222 Networking diagram of CQ typical configuration 1Configure Router A [RouterA]acl 105 [RouterA-acl-105]rule normal permit ip source 10.1.4.0 0.0.0.255 destination 10.1.5.0 0.0.0.255 [RouterA-acl-105] rule normal deny ip source any destination any [RouterA-acl-105]acl 107 [RouterA-acl-107] rule normal permit ip source 192.168.0.2 0.0.0.0 destination 192.168.0.1 0.0.0.0 [RouterA-acl-108]rule normal permit ip source 192.168.1.2 0.0.0.0 destination 192.168.1.1 0.0.0.0 aConfigure the CQ queue [RouterA] qos cql 1 queue 1 queue-length 100 [RouterA] qos cql 1 queue 1 serving 5000 [RouterA] qos cql 1 queue 2 queue-length 100 [RouterA] qos cql 1 queue 2 serving 1000 [RouterA] qos cql 1 protocol ip acl 107 queue 1 [RouterA] qos cql 1 protocol ip acl 108 queue 2 bConfigure Serial0 master/slave addresses [RouterA-Serial0] ip address 192.168.0.1 255.255.255.252 [RouterA-Serial0] ip address 192.168.1.1 255.255.255.252 sub cApply the CQ queue 1 to Serial0 [RouterA-Serial0] qos cq cql dConfigure Tunnel0 [RouterA-Tunnel0] ip address 10.1.1.1 255.255.255.0 [RouterA-Tunnel0] source 192.168.0.1 [RouterA-Tunnel0] destination 192.168.0.2 eConfigure Tunnel1 [RouterA-Tunnel1] ip address 10.1.7.1 255.255.255.0 [RouterA-Tunnel1] source 192.168.1.1 [RouterA-Tunnel1] destination 192.168.1.2 2Configure Router B aConfigure the access control list [RouterB]acl 105 PC1:10.1.3.10 PC3:10.1.4.10PC2:10.1.5.10 PC4:10.1.6.10e0:10.1.5.1 e1:10.1.6.1 e0.0:10.1.3.1 e0.1:10.1.4.1 (10.1.1.1) tunnel0 (10.1.1.2) RouterRouter(10.1.7.1) tunnel1 (10.1.7.2)s0:192.168.0.1 s0:192.168.0.2
Congestion Management Configuration Examples695 [RouterB-acl-105]rule normal permit ip source 10.1.5.0 0.0.0.255 destination 10.1.4.0 0.0.0.255 [RouterB-acl-105] rule normal deny ip source any destination any [RouterB-acl-105]acl 107 [RouterB-acl-107]rule normal permit ip source 192.168.0.1 0.0.0.0 destination 192.168.0.2 0.0.0.0 [RouterB-acl-107]acl 108 [RouterB-acl-107]rule normal permit ip source 192.168.1.1 0.0.0.0 destination 192.168.1.2 0.0.0.0 bConfigure the CQ queue [RouterB] qos cql 1 queue 1 queue-length 100 [RouterB] qos cql 1 queue 1 serving 5000 [RouterB] qos cql 1 queue 2 queue-length 100 [RouterB] qos cql 1 queue 2 serving 1000 [RouterB] qos cql 1 protocol ip acl 107 queue 1 [RouterB] qos cql 1 protocol ip acl 108 queue 2 (CQ restricts the traffic in Tunnel0 that is larger than that in tunnel1, and CQ is effective at the exit) cConfigure Serial0 master/slave addresses [RouterB-Serial0] ip address 192.168.0.2 255.255.255.252 [RouterB-Serial0] ip address 192.168.1.2 255.255.255.252 sub dApply the CQ queue 1 to Serial0 [RouterB-Serial0] qos cq cql 1 eConfigure Tunnel0 [RouterB-Tunnel0] ip address 10.1.2.1 255.255.255.0 [RouterB-Tunnel0] source 192.168.0.2 [RouterB-Tunnel0] destination 192.168.0.1 fConfigure Tunnel1 [RouterB-Tunnel1] ip address 10.1.7.2 255.255.255.0 [RouterB-Tunnel1] source 192.168.1.2 [RouterB-Tunnel1] destination 192.168.1.1 WFQ Configuration Example 1Configure a WFQ queue with congestion discard threshold as 64 packets and 512 dynamic queues. [Router] interface ethernet 0 [Router-Ethernet0] qos wfq queue-length 64 queue-number 512