- Allied Telesis, Inc Switches Owner's Manual

Page 13 | AlliedWare™ OS How To Note: QoS configuration
Full QoS scenario 1 : tiered services for a single customer
Full QoS scenario 1 : tiered services for a single
customer
In this section, we will build up a relatively complex QoS configuration to support a scenario
requiring quite precise control over the traffic passing through the switch.
The scenario is an ISP providing connectivity for a customer, and offering different levels of
service for different types of traffic.
The customer is connected to port
1 of the switch, and the uplink to the ISP is on port 24 of
the switch.
The service offered by the ISP puts a limit on the total bandwidth of traffic that the customer
can send to the ISP.
This is achieved by setting a maximum bandwidth on the uplink port:
set switch port=24 egresslimit=<limit>
The deal offered to the customer is that their traffic will be treated as belonging to three
categories, and each category of traffic will be given a different level of service:
Gold traffic will be limited to, say, 2Mbps, but the ISP will guarantee delivery of the traffic
across their network, with a low latency.
Silver traffic will not have a particular limit (i.e. it can burst up to the max egress bandwidth
of the uplink port), but when congestion occurs, it will be throttled back in favour of Gold
traffic, if necessary. The ISP will guarantee to deliver up to, say 5Mbps of Silver traffic across
its network 90% of the time, but will give no guarantees about latency.
X Step 1 —Set the egress bandwidth limiting
X Step 2—Give better service to some types of traffic than to others
Port 24
uplink to the ISP
Customer LAN
ISP