Allied Telesis Switchblade AT-x900-12 User manual

AlliedWare PlusTM OS
How To |
C613-16112-00 REV A www.alliedtelesis.com
Introduction
This document describes some generic configuration examples for Quality of Service (QoS)
on the AlliedWare Plus OS.
What information will you find in this document?
This document provides information in the following sections:
•1. Setting the egress rate‚ on page 2
•2. Setting the priority on a packet‚ on page 7
•3. Setting the egress queues‚ on page 10
•Full QoS scenario - tiered services for a single customer‚ on page 13
Which product and software version does this information apply to?
This How To Note applies to the following Allied Telesis switches, running the
AlliedWare Plus OS software version 5.2.
1 or later:
•SwitchBlade x908
•x900 series
Configure QoS on x900-24, x900-12, and
SwitchBlade x908 Series Switches

Page 2 | AlliedWare Plus™ OS How To Note: QoS
1. Setting the egress rate
1. Setting the egress rate
Example 1-1: Setting the egress limit of a switch port
Commands:
interface port1.0.24
egress-rate-limit 25m
These commands will set the egress limit of port 24 to 25Mbps. The granularity is 651kbps.
Port 24

Page 3 | AlliedWare Plus™ OS How To Note: QoS
1. Setting the egress rate
Example 1-2: setting the maximum bandwidth limit per ingress port
Ingress rate limiting cannot be configured on the port per se, but is achieved by creating a QoS
policy with a bandwidth limited traffic class, and applying that policy to each port.
This set of commands will set the ingress rate of traffic received per port from ports 1 to 20 to
various different values. Note that the class-map matches EVERY packet. The granularity of the rate
limiting is around 1 kbps.
mls qos enable
class-map cmap1
policy-map pmap1
class cmap1
police single-rate 128 3000 5000 exceed-action drop
policy-map pmap2
class cmap1
police single-rate 256 3000 5000 exceed-action drop
policy-map pmap3
class cmap1
police single-rate 64 3000 5000 exceed-action drop
.
.
.
policy-map pmap20
class cmap1
police single-rate 512 3000 5000 exceed-action drop
interface port1.0.1
service-policy input pmap1
interface port1.0.2
service-policy input pmap2
interface port1.0.3
service-policy input pmap3
.
.
.
interface port1.0.20
service-policy input pmap20
Port 24
Ingress ports 1-20

Page 4 | AlliedWare Plus™ OS How To Note: QoS
1. Setting the egress rate
Example 1-3: Setting the maximum bandwidth limit for each user
In example 1-1, we configured an egress rate on ports. But the granularity of that bandwidth limiting
was multiples of 651kbps. It is possible to achieve finer-grained limiting using the devices advanced
QoS capability. In this example we assume that there is one device with a known IP address,
attached to each port. Policers will be configured to provide bandwidth limiting.
This set of commands will set the total egress limit (download traffic) for each user to 256kbps. The
granularity is around 1kbps.
mls qos enable
access-list 3011 permit ip any 192.168.1.1/32
access-list 3012 permit ip any 192.168.1.2/32
access-list 3013 permit ip any 192.168.1.3/32
.
.
.
class-map cmap1
match access-group 3011
class-map cmap2
match access-group 3012
class-map cmap3
match access-group 3013
.
.
.
policy-map pmap1
class cmap1
police single-rate 256 3000 5000 exceed-action drop
class cmap2
police single-rate 256 3000 5000 exceed-action drop
class cmap3
police single-rate 256 3000 5000 exceed-action drop
.
.
.
interface port1.0.24
service-policy input pmap1
Port 24
Internet
connection
Users connected to the switch downloading files fromthe Internet
(192.168.1.1-192.168.1.25)

Page 5 | AlliedWare Plus™ OS How To Note: QoS
1. Setting the egress rate
Example 1-4: Setting the maximum bandwidth limit for each IP subnet
This example is very similar to example 1-3, except that it is assumed that a whole subnet is
attached to each port, not just a single device on each port.
This set of commands will set the total egress limit (download traffic) for each subnet to 256kbps.
The granularity is around 1kbps.
mls qos enable
access-list 3011 permit ip any 192.168.1.0/24
access-list 3012 permit ip any 192.168.1.0/24
access-list 3013 permit ip any 192.168.1.0/24
.
.
.
class-map cmap1
match access-group 3011
class-map cmap2
match access-group 3012
class-map cmap3
match access-group 3013
.
.
.
policy-map pmap1
class cmap1
police single-rate 256 3000 5000 exceed-action drop
class cmap2
police single-rate 256 3000 5000 exceed-action drop
class cmap3
police single-rate 256 3000 5000 exceed-action drop
.
.
.
interface port1.0.24
service-policy input pmap1
Port 24
Internet
connection
Users connected to the switch downloading files fromthe Internet
(192.168.1.0/24 - 192.168.23.0/24)

Page 6 | AlliedWare Plus™ OS How To Note: QoS
1. Setting the egress rate
Example 1-5: Setting the maximum bandwidth limit of VLANs
mls qos enable
class-map cmap2
match vlan 2
class-map cmap3
match vlan 3
class-map cmap4
match vlan 4
mls qos enable
mls qos aggregate-police agg1 single-rate 256 3000 5000 exceed-action drop
mls qos aggregate-police agg2 single-rate 256 3000 5000 exceed-action drop
mls qos aggregate-police agg3 single-rate 256 3000 5000 exceed-action drop
policy-map pmap1
class cmap2
police aggregate agg1
class cmap3
police aggregate agg2
class cmap4
police aggregate agg3
interface port1.0.1-1.0.20
service-policy input pmap1
Port 24
Ingress ports 1-20 (these ports are carrying a mixture of
VLAN2, VLAN3 and VLAN4 packets, either with or without VLAN tags)

Page 7 | AlliedWare Plus™ OS How To Note: QoS
2. Setting the priority on a packet
2. Setting the priority on a packet
Example 2-1: Setting the Layer 2 (VLAN/802.1p) priority per ingress port
Here we assign different 802.1p values to packets arriving on different ports.
These values are also known as the Layer 2 (L2) or VLAN priority.
mls qos enable
class-map cmap1
policy-map pmap1
class cmap1
set cos 6
policy-map pmap2
class cmap1
set cos 5
policy-map pmap3
class cmap1
set cos 4
.
.
.
interface port1.0.1
service-policy input pmap1
interface port1.0.2
service-policy input pmap2
interface port1.0.3
service-policy input pmap3
.
.
.
Port 24
Ingress ports 1-20 (these ports MAY be carrying a mixture of
packets fromdifferent VLANs, either with or without VLAN tags)

Page 8 | AlliedWare Plus™ OS How To Note: QoS
2. Setting the priority on a packet
Example 2-2: Setting the Layer 2 (VLAN/802.1p) priority per VLAN
This set of commands will set the Layer 2 priority of VLAN2, VLAN3 and VLAN4 traffics packets,
received on ports 1 to 20, to 6, 5 and 4 respectively.
mls qos enable
class-map cmap2
match vlan 2
class-map cmap3
match vlan 3
class-map cmap4
match vlan 4
policy-map pmap1
class cmap2
set cos 6
class cmap3
set cos 5
class cmap4
set cos 4
interface port1.0.1-1.0.20
service-policy input pmap1
Port 24
Ingress ports 1-20 (these ports MAY be carrying a mixture ofVLAN2,
VLAN3, and VLAN4 packets either with or without VLAN tags)

Page 9 | AlliedWare Plus™ OS How To Note: QoS
2. Setting the priority on a packet
Example 2-3: Setting the Layer 3 (TOS/DCSP) priority per ingress port
Use the same configuration provided in Example 2-1 on page 7, but change the following line:
set cos <cos-value>
to
set dscp <dscp-value>
Example 2-4: Setting the Layer 3 (TOS/DSCP) priority per VLAN
Use the same configuration provided in Example 2-2 on page 8, but change the following line:
set cos <cos-value>
to
set dscp <dscp-value>

Page 10 | AlliedWare Plus™ OS How To Note: QoS
3. Setting the egress queues
3. Setting the egress queues
In this section we look at methods for directing certain packets into certain queues on the egress
port.
Example 3-1: Setting the egress queue according to the L2 priority of the
incoming packet
The priority-to-queue map is a straightforward method for assigning packets to egress queues on
the basis of the packets’ 802.1p values.
Command
settings
The map cos-queue commands in the above example set the mapping between the VLAN Tag
User Priorities of the packets and the egress queues. Priorities 0 to 7 are mapped to queues 2, 3, 1,
0, 4, 5, 6 and 7 respectively.
The Interface mode command sets the incoming ports to send untagged packets to queue number
2, which means the untagged packets will use the same queue as the tagged packets with a User
Priority of 1.
mls qos enable
mls qos map cos-queue 0 2
mls qos map cos-queue 1 3
mls qos map cos-queue 2 1
mls qos map cos-queue 3 0
mls qos map cos-queue 4 4
mls qos map cos-queue 5 5
mls qos map cos-queue 6 6
mls qos map cos-queue 7 7
interface port1.0.1-port1.0.20
mls qos queue 2
Port 24
Ingress ports 1-20 (these ports MAY be carrying a mixture ofpackets
fromdifferent VLAN packets either with or without VLAN tags)