NETGEAR AV Line M4250 GSM4210PX 8-Port Gigabit PoE+ Compliant Managed AV Switch with SFP (220W) - Manual (Page 464)

Table 133. CoS Interface Queue Drop Precedence Status (Continued)
Description Field
The WRED maximum queue threshold value. WRED Maximum Threshold
The WRED packet drop probability value. WRED Drop Probability Scale
Differentiated Services
The QoS feature contains Differentiated Services (DiffServ) support that allows traffic to
be classified into streams and given certain QoS treatment in accordance with defined
per-hop behaviors.
Standard IP-based networks provide best-effort data delivery service. Best-effort service
implies that the network delivers the data in a timely fashion, although there is no
guarantee. If congestion occurs, packets might be delayed, sent sporadically, or dropped.
For typical Internet applications, such as email and file transfers, a slight degradation
in service is acceptable and in many cases unnoticeable. However, any degradation of
service can negatively affect applications with strict timing requirements, such as voice
and multimedia.
Defining DiffServ
To use DiffServ for QoS, you must first define the following categories and their criteria:
1. Class: Create classes and define class criteria.
2. Policy: Create policies, associate classes with policies, and define policy statements.
3. Service: Add a policy to an inbound interface.
Packets are classified and processed based on defined criteria. The classification criteria
are defined by a class. The processing is defined by a policy’s attributes. Policy attributes
can be defined on a per-class instance basis, and it is these attributes that are applied
when a match occurs. A policy can contain multiples classes. When the policy is active,
the actions taken depend on which class matches the packet.
Note the following about the DiffServ process:
• Packets are filtered and processed based on defined criteria. The filtering criteria is
defined by a class. The processing is defined by a policy's attributes. Policy attributes
Main User Manual 464 Configure Quality of Service
AV Line of Fully Managed Switches M4250 Series Main User Manual