User`s manual

MP-202 Telephone Adapter 70 Document #: LTRT-50605
User's Manual
8.3 DSCP Mapping
In order to understand what is Differentiated Services Code Point (DSCP), one must first
be familiarized with the Differentiated Services model.
Differentiated Services (Diffserv) is a Class of Service (CoS) model that enhances best-
effort Internet services by differentiating traffic by users, service requirements and other
criteria. Packets are specifically marked, allowing network nodes to provide different levels
of service, as appropriate for voice calls, video playback or other delay-sensitive
applications, via priority queuing or bandwidth allocation, or by choosing dedicated routes
for specific traffic flows.
Diffserv defines a field in IP packet headers referred to as DSCP. Hosts or routers passing
traffic to a Diffserv-enabled network will typically mark each transmitted packet with an
appropriate DSCP. The DSCP markings are used by Diffserv network routers to
appropriately classify packets and to apply particular queue handling or scheduling
behavior.
The gateway provides a table of predefined DSCP values, which are mapped to 802.1p
priority marking method. You can edit or delete any of the existing DSCP setting, as well as
add new entries.
1. Press the QoS button on the sidebar and then click the DSCP Settings tab. The
following screen will appear (refer to the figure).
Figure 8-8: QoS - DSCP Settings