MP-202 Telephone Adapter
72
LTRT-50604
MP-202
2.
To edit an existing entry, click its Edit action icon. To add a new entry, click the New
Entry link. In both cases, the ’Edit DSCP Settings’ screen will appear (refer to the
figure).
Figure
8-9: QoS - Edit DSCP Settings
3.
Configure the following fields:
Table
8-5: Edit DSCP Settings- Parameter Descriptions
Parameter
Description
DSCP Value (hex)
Enter a hexadecimal number that will serve as the
DSCP value.
802.1p Priority
Select a 802.1p priority level from the combo box
(each priority level is mapped to low/medium/high
priority).
Click ‘OK’ to save the settings.
Note that the DSCP value overriding the priority of incoming packets with an unassigned
value (priority 0, assumed to be a no-priority-set) is ‘0x0’ (refer to the figure). By default,
this value is mapped to 802.1p priority level ‘0 -Low’, which means that such packets will
receive the lowest priority.
8.4 802.1p
Mapping
The IEEE 802.1p priority marking method is a standard for prioritizing network traffic at the
data link/Mac sub-layer. 802.1p traffic is simply classified and sent to the destination, with
no bandwidth reservations established.
The 802.1p header includes a 3-bit prioritization field, which allows packets to be grouped
into eight levels of priority. The gateway maps these eight levels to three main priorities:
high, medium and low. By default, values six and seven are mapped to high priority, which
may be assigned to network-critical traffic. Values four and five are mapped to medium
priority, which may be applied to delay-sensitive applications, such as interactive video and
voice. Values three to zero are mapped to low priority, which may range from controlled-
load applications down to ‘loss eligible’ traffic. The zero value is normally used for best-
effort traffic. It is the default value for traffic with unassigned priority.