ZyXEL Communications MAX208M2W SERIES, User Manual

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Chapter 9 The VoIP General Screens
MAX208M2W Series User ’ s Guide
137
9.2.2 QoS Settings
Click VoIP > General > QoS to set up Type of Service (ToS) and Differentiated
Services (Diffserv) settings for voice traffic transmission through the MAX208M2W
Series.
Figure 61 VoIP > General > QoS
The following table describes the labels in this screen.
9.3 Technical Reference
The following section contains additional technical information about the
MAX208M2W Series features described in this chapter.
9.3.1 DSCP and Per-Hop Behavior
DiffServ defines a new DS (Differentiated Services) field to replace the Type of
Service (TOS) field in the IP header. The DS field contains a 2-bit unused field and
a 6-bit DSCP field which can define up to 64 service levels. The following figure
illustrates the DS field.
Figure 62 DiffServ: Differentiated Service Field
DSCP is backward compatible with the three precedence bits in the ToS octet so
that non-DiffServ compliant, ToS-enabled network device will not conflict with the
DSCP mapping.
Table 48 VoIP > General > QoS
LABEL DESCRIPTION
SIP ToS/
DiffServ Enter the first 6 bits of the ToS field in hexadecimal (in a format of
0x00), which you want to mark on all outgoing SIP packets flowing
through the MAX208M2W Series. The MAX208M2W Series automatically
converts this number to another in order to compatible with DiffServ-
enabled network. For example, if you enter 0x2E, it is 101110 in binary
for ToS service. The MAX208M2W Series converts it to 10111000 in
binary for DiffServ-enabled network.
RTP ToS/
DiffServ Select the ToS value in hexadecimal (in a format of 0x00) to mark all
outgoing RTP packets flowing through the MAX208M2W Series.
DSCP
(6-bit)
Unused
(2-bit)