Quality Of Service - NetModule NB3700 User Manual

5.4.5. Quality Of Service

NetModule routers are able to prioritize and shape certain kinds of IP traffic. This is
currently limited on egress, which means that only outgoing traffic can be stipulated.
The current QoS solution is using Stochastic Fairness Queueing (SFQ) classes in com-
bination with Hierarchy Token Bucket (HTB) qdiscs. Its principle of operation can be
summarized as ceiling the max. throughput per link and shaping traffic by reflecting
the specified queue priorities. In general, the lowest priority of a queue gets most out of
the available bandwidth.
In case of demands for other class or qdisc algorithms please contact our support team
in order to evaluate the best approach for your application.
QoS Administration
The administration page can be used to enable and disable QoS.
QoS Classification
The classification section can be used to define the WAN interfaces on which QoS should
be active.
Parameter
Interface
Bandwidth congestion
Downstream bandwidth The available bandwidth for incoming traffic
Upstream bandwidth
When defining limits, you should consider bandwidth limits which are at least possible as
most shaping and queues algorithms will not work correctly if the specified limits cannot
be achieved. In particular, any WWAN interfaces operating in a mobile enviroment are
suffering variable bandwidths, thus rather lower values should be used.
In case an interface has been activated, the system will automatically create the following
queues:
Parameter
high
default
NB3700 User Manual 3.8
QoS Interface Parameters
The WAN interface on which QoS should be active
The bandwidth congestion method. In case of auto the
system will try to apply limits in a best-effort way. However,
it is suggested to set fixed bandwidth limits as they also offer
a way of tuning the QoS behaviour.
The available bandwidth for outgoing traffic
QoS Default Queues
A high priority queue which may hold any latency-critical
services (such as VoIP)
A default queue which will handle all other services
70