Quality Of Service (Qos); Network Traffic; Bandwidth Reservation Or Limitation (Cbq); Queues - Stormshield SN series Configuration Manual

QUALITY OF SERVICE (QoS)

The configuration window for quality of service consists of a single screen.

Network traffic

An important element of Quality of Service is the resolution of a major issue – the high rate of
packet loss over the internet. When a packet is lost before it reaches its destination, the resources
involved in its transmission will be wasted. In certain cases, this can even lead to severe
congestion which may completely paralyze the systems.
The need for the stability and "real time" of videoconferencing applications is no longer the case
today. The optimized control of congestion and the management of data queues has become a
major challenge in Quality of Service.
Stormshield Network Firewalls employ two algorithms for congestion management – TailDrop and
BLUE. However, Stormshield Network recommends the use of BLUE for managing congestion.
Treatment when full
The Default queue setting has been removed from the web administration interface, as it
could enable QoS on all of the firewall's interfaces. This option has been kept as an
advanced property via the serverd command line.
This option allows selecting the default queue from the choice of defined queues. More
precisely, this option allows choosing how the default traffic (which does not correspond
to any queue) will be treated in relation to the rest of the traffic. By default, this traffic type
has priority over traffic treated by QoS ("Top priority"), but it is possible to subject the traffic
to a certain queue by selecting it from this drop-down list.

Bandwidth reservation or limitation (CBQ)

Total bandwidth
"ACK" and "low delay" packets are treated with a higher default priority (in order to speed up the
transfer of data through limited bandwidth).

Queues

The QoS module embedded in Stormshield Network's intrusion prevention engine is associated
with the Filter module in order to provide Quality of Service functions.
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This option allows defining the congestion treatment algorithm, which aims to prevent
slowdowns.
REMARK
The reference value in Kbits/s or en Mbits/s allows indicating a reference on which
bandwidth restrictions, indicated in percentage in the configuration of queues, will be
based.
IMPORTANT
This value will restrict all traffic subject to QoS. The sum of all traffic passing
through QoS will not be able to exceed this value and any excess network
packets will be eliminated. It is therefore very important to set a reference
value suited to the throughput of the network interface in question.
SNS - USER CONFIGURATION MANUAL V.3
sns-en-user_configuration_manual-v3 - Copyright © Stormshield 2016
QUALITY OF SERVICE (QOS)