Quality Of Service - Draytek Vigor2800 Series User Manual

The reminder as regards concern about Firewall and UPnP
Can't work with Firewall Software
Enabling firewall applications on your PC may cause the UPnP function not
working properly. This is because these applications will block the accessing ability
of some network ports.
Security Considerations
Activating the UPnP function on your network may incur some security threats. You
should consider carefully these risks before activating the UPnP function.
Some Microsoft operating systems have found out the UPnP weaknesses and
hence you need to ensure that you have applied the latest service packs and
patches.
Non-privileged users can control some router functions, including removing
and adding port mappings.
The UPnP function dynamically adds port mappings on behalf of some UPnP-aware
applications. When the applications terminate abnormally, these mappings may not
be removed.
3 . 5 . 5 Q u a l i t y
3 . 5 . 5 Q u a l i t y
Deploying QoS (Quality of Service) management to guarantee that all applications receive the
service levels required and sufficient bandwidth to meet performance expectations is indeed
one important aspect of modern enterprise network.
One reason for QoS is that numerous TCP-based applications tend to continually increase their
transmission rate and consume all available bandwidth, which is called TCP slow start. If
other applications are not protected by QoS, it will detract much from their performance in the
overcrowded network. This is especially essential to those are low tolerant of loss, delay or
jitter (delay variation), such as voice over IP, videoconferencing, streaming video or data.
Another reason is due to congestions at network intersections where speeds of interconnected
circuits mismatch or traffic aggregates, packets will queue up and traffic can be throttled back
to a lower speed. If there's no defined priority to specify which packets should be discarded
(or in another term "dropped") from an overflowing queue, packets of sensitive applications
mentioned above might be the ones to drop off. How this will affect application performance?
Vigor2800 Series User's Guide
o f S e r v i c e
o f S e r v i c e
59