Configuring MQC to Implement Congestion Management
Context
- AF: ensures a low drop probability of packets when the rate of outgoing service traffic does not exceed the minimum bandwidth. It is applied to services of heavy traffic that needs to be ensured.
EF/LLQ: is applied to services requiring a low delay, low drop probability, and assured bandwidth. EF or LLQ is also applied to services occupying low bandwidth, for example, voice packets. After packets matching traffic classification rules enter EF or LLQ queues, they are scheduled in Strict Priority (SP) mode. Packets in other queues are scheduled only after all the packets in EF or LLQ queues are scheduled. When AF or BE queues have idle bandwidth, EF queues can occupy the idle bandwidth.
Compared with EF, LLQ provides shorter delay.
- BE: is used with the default traffic classifier. The remaining packets that do not enter AF or EF queues enter BE queues. BE queues use WFQ scheduling. When a greater number of queues are configured, WFQ allocates bandwidth more evenly but more resources are occupied. WFQ is applied to the services insensitive to the delay and packet loss, for example, Internet access services.
- When the default traffic classifier is associated with AF queues:
- The total bandwidth used by AF and EF queues cannot exceed the interface bandwidth.
AF queues share the remaining bandwidth based on their weights. The remaining bandwidth is calculated as follows:
Remaining bandwidth = Available bandwidth — Bandwidth used by EF queues
- When the default traffic classifier is associated with BE queues:
- If the bandwidth percentage is used to configure the minimum bandwidth for AF queues:
- The system allocates 10% of the interface's available bandwidth to BE queues.
- The bandwidth used by AF and EF queues cannot exceed 99% of the interface bandwidth.
- When the percentage of bandwidths of AF and EF queues to the interface's available bandwidth is less than 90%, the system allocates 10% of the interface's available bandwidth to BE queues by default.
- When the percentage of bandwidths of AF and EF queues to the interface's available bandwidth is larger than 90% (for example, A%), the system allocates A% subtracted from 100% of the bandwidth to BE queues by default.
AF and BE queues share the remaining bandwidth based on their weights. The remaining bandwidth is calculated as follows:
Remaining bandwidth = Available bandwidth — Bandwidth used by EF queues
- If the bandwidth is used to configure the minimum bandwidth for AF queues, AF and BE queues share the remaining bandwidth in the ratio of 9:1. The remaining bandwidth refers to the bandwidth occupied by EF queues that is subtracted from the available bandwidth.
- If the bandwidth percentage is used to configure the minimum bandwidth for AF queues:
The system allocates bandwidth to queues based on their weights.
Table 4-5 provides an example of bandwidth allocation.
Interface's Available Bandwidth |
Configuration |
|---|---|
100 Mbit/s |
EF queues: a minimum of 50% of the interface bandwidth |
AF queues: a minimum bandwidth of 30 Mbit/s |
|
BE queues: 1/9 of the bandwidth for AF queues by default when the default traffic classifier is associated with BE queues |
- Bandwidth of EF queues: 100 Mbit/s x 50% = 50 Mbit/s
- Remaining bandwidth: 100 Mbit/s - 50 Mbit/s = 50 Mbit/s
- AF queues and BE queues share the remaining bandwidth in the proportion of 9:1:
- Bandwidth of AF queues: 50 Mbit/s x [9/(9+1)]= 45 Mbit/s
- Bandwidth of BE queues: 50 Mbit/s x [1/(9+1)]= 5 Mbit/s
CBQ Configuration |
Whether the Queue Profile Can Be Configured (qos queue-profile) |
Whether Traffic Shaping Can Be Configured (qos gts or qos gts adaptation-profile) |
|---|---|---|
Main interface |
Main interface: No |
Main interface: Yes |
Sub-interface: No |
Sub-interface: No |
|
Sub-interface |
Main interface: Yes |
Main interface: Yes |
Sub-interface: No |
Sub-interface: Yes |
Procedure
- Configure a traffic classifier.
Run system-view
The system view is displayed.
Run traffic classifier classifier-name [ operator { and | or } ]
A traffic classifier is created and the traffic classifier view is displayed.
and indicates that rules are ANDed with each other.If a traffic classifier contains ACL rules, packets match the traffic classifier only when they match one ACL rule and all the non-ACL rules.
If a traffic classifier does not contain ACL rules, packets match the traffic classifier only when the packets match all the non-ACL rules.
By default, the relationship between rules in a traffic classifier is OR.
- Run the following commands as required.
Matching Rule
Command
Outer VLAN ID
if-match vlan-id start-vlan-id [ to end-vlan-id ]
Inner VLAN IDs in QinQ packets
if-match cvlan-id start-vlan-id [ to end-vlan-id ]
802.1p priority in VLAN packets
if-match 8021p 8021p-value &<1-8>
Inner 802.1p priority in QinQ packets
if-match cvlan-8021p 8021p-value &<1-8>
EXP priority in MPLS packets
if-match mpls-exp exp-value &<1-8>
NOTE:V300R019C10 and earlier versions: Only the AR600 series does not support MPLS. V300R019C11 and later versions: Only the AR611W, AR611W-LTE4CN, AR617VW, AR617VW-LTE4EA, AR617VW-LTE4, AR651C, and AR651F-Lite do not support MPLS.
Destination MAC address
if-match destination-mac mac-address [ mac-address-mask mac-address-mask ]
Source MAC address
if-match source-mac mac-address [ mac-address-mask mac-address-mask ]
DLCI value in FR packets
if-match dlci start-dlci-number [ to end-dlci-number ]
DE value in FR packets
if-match fr-de
NOTE:AR600 and AR1600 series do not support fr-de.
Protocol type field encapsulated in the Ethernet frame header
if-match l2-protocol { arp | ip | mpls | rarp | protocol-value }
All packets
if-match any
DSCP priority in IP packets
if-match [ ipv6 ] dscp dscp-value &<1-8>
IP precedence in IP packets
if-match ip-precedence ip-precedence-value &<1-8>
NOTE:if-match [ ipv6 ] dscp and if-match ip-precedence cannot be configured simultaneously in a traffic classifier where the relationship between rules is AND.
Layer 3 protocol type
if-match protocol { ip | ipv6 }
QoS group index of packets
if-match qos-group qos-group-value
NHRP group name of packets
if-match nhrp-group nhrp-group-name
IPv4 packet length
if-match packet-length min-length [ to max-length ]
PVC information in ATM packets
if-match pvc vpi-number/vci-number
RTP port number
if-match rtp start-port start-port-number end-port end-port-number
SYN Flag in the TCP packet header
if-match tcp syn-flag { ack | fin | psh | rst | syn | urg } *
Inbound interface
if-match inbound-interface interface-type interface-number
Outbound interface
if-match outbound-interface Cellular interface-number:channel
ACL rule
if-match acl { acl-number | acl-name }
NOTE:Before defining a matching rule for traffic classification based on an ACL, create the ACL.
To use an ACL in a traffic classifier to match the source IP address, run the qos pre-nat command on an interface to configure NAT pre-classification. NAT pre-classification enables the NAT-enabled device to carry the private IP address before translation on the outbound interface so that the NAT-enabled device can classify IP packets based on private IP addresses and provide differentiated services.
ACL6 rule
if-match ipv6 acl { acl-number | acl-name }
NOTE:Before defining a matching rule for traffic classification based on an ACL, create the ACL.
To use an ACL in a traffic classifier to match the source IP address, run the qos pre-nat command on an interface to configure NAT pre-classification. NAT pre-classification enables the NAT-enabled device to carry the private IP address before translation on the outbound interface so that the NAT-enabled device can classify IP packets based on private IP addresses and provide differentiated services.
Application protocol
if-match application application-name [ user-set user-set-name ] [ time-range time-name ]
NOTE:Before defining a matching rule based on an application protocol, enable Smart Application Control (SA) and load the signature file.
SA group
if-match category category-name [ user-set user-set-name ] [ time-range time-name ]
NOTE:Before defining a matching rule based on an application protocol, enable Smart Application Control (SA) and load the signature file.
User group
if-match user-set user-set-name [ time-range time-range-name ]
NOTE:- Only the AR600 series supports user-set.
- The user-set command can be configured only on the web UI in V300R019C10 and later versions. Therefore, you are advised to configure other commands related to user-set on the web UI. Otherwise, the configuration may fail.
Run quit
Exit from the traffic classifier view.
- Configure a traffic behavior.
Run traffic behavior behavior-name
A traffic behavior is created and the traffic behavior view is displayed.
Run the following commands as required.
Run queue af bandwidth [ remaining ] { bandwidth | pct percentage }
AF is configured for packets of a certain type and the minimum bandwidth is set.
Run queue ef bandwidth { bandwidth [ cbs cbs-value ] | pct percentage [ cbs cbs-value ] }
EF is configured for packets of a certain type and the maximum bandwidth is set.
Run queue llq bandwidth { bandwidth [ cbs cbs-value ] | pct percentage [ cbs cbs-value ] }
LLQ is configured for packets of a certain type and the maximum bandwidth is set.
Run queue wfq [ queue-number total-queue-number ]
The device is configured to send packets matching the default traffic classifier to BE queues in WFQ mode and the number of queues is set.
(Optional) Run queue-length { bytes bytes-value | packets packets-value }*
The maximum length of a queue is set.
You cannot use the queue-length command to set the length for LLQ queues.
(Optional) Run statistic enable
The traffic statistics function is enabled.
Run quit
Exit from the traffic behavior view.
Run quit
Exit from the system view.
- Configure a traffic policy.
Run system-view
The system view is displayed.
Run traffic policy policy-name
A traffic policy is created and the traffic policy view is displayed, or the view of an existing traffic policy is displayed.
By default, no traffic policy is created in the system.
Run classifier classifier-name behavior behavior-name [ precedence precedence-value ]
A traffic behavior is bound to a traffic classifier in a traffic policy.
By default, no traffic classifier or traffic behavior is bound to a traffic policy.
Run quit
Exit from the traffic policy view.
Run quit
Exit from the system view.
- Apply the traffic policy.
Apply a traffic policy to an interface.
Run system-view
The system view is displayed.
Run interface interface-type interface-number[.subinterface-number ]
The interface view is displayed.
- Apply a traffic policy to the interface. You can apply one or three types of traffic policies to one direction of the interface.
Run traffic-policy policy-name { inbound | outbound }
A common traffic policy is applied to the outbound or inbound direction of the interface.
By default, no common traffic policy is applied to an interface.
Run traffic-policy policy-name { inbound | outbound } preprocess
A preprocessing traffic policy is applied to the outbound or inbound direction of the interface.
By default, no preprocessing traffic policy is applied to an interface.
Run traffic-policy policy-name { inbound | outbound } firstprocess
A preferential processing traffic policy is applied to the outbound or inbound direction of the interface.
By default, no preferential processing traffic policy is applied to an interface.
The preprocess and firstprocess parameters can be configured only for Layer 3 interfaces.
- Apply a traffic policy to an interzone.
Run system-view
The system view is displayed.
- Run firewall interzone zone-name1 zone-name2
An interzone is created and the interzone view is displayed.
By default, no interzone is created.
To create an interzone, you must specify two existing security zones.
Run traffic-policy policy-name
A traffic policy is bound to the interzone.
By default, no traffic policy is bound to an interzone.
- Apply a traffic policy to a bridge domain (BD).
Run system-view
The system view is displayed.
Run bridge-domain bd-id
A BD is created and the BD view is displayed.
By default, no BD is created.
Run traffic-policy policy-name { inbound | outbound }
A traffic policy is applied to the BD.
By default, no traffic policy is applied to a BD.
- Apply a traffic policy in the system view.
Run system-view
The system view is displayed.
Run traffic-policy policy-name global bind interface { interface-type interface-number } &<1-16>
A global traffic policy is applied to the interface and bound to an interface.
By default, no global traffic policy is applied to the device or bound to an interface.
