User's Manual Part 2

Chapter 9 The VoIP General Screens
BM2022w User’s Guide
160
9.3 QoS
This section describes the features of the Quality of Service (QoS) screen.
Click VoIP > General > QoS to set up Type of Service (ToS) and Differentiated Services (Diffserv)
settings for voice traffic transmission through the BM2022w.
Figure 87 VoIP > General > QoS
The following table describes the labels in this screen.
Voice Jitter Buffer
Type
Voice jitter is a variation in delay of RTP packets delivery. This could cause
strange sound effects. The BM2022w can utilize the following types of jitter
buffer to minimize the effects of jitter.
Dynamic - Jitter buffer size is dynamically changed by RTP packets delivery
status.
Static - Jitter buffer size is fixed.
Voice Jitter Buffer
Length
Select the maximum number of milliseconds of voice traffic the BM2022w can
help to smooth out the jitter in order to ensure good voice quality for your
conversations.
Packet Loss
Concealment
Packets may be dropped due to an overwhelming amount of traffic on the
network. Some degree of packet loss will not be noticeable to the end user, but
as packet loss increases the quality of sound degrades. Select this to have the
BM2022w to improve the voice quality when packet loss occurs.
T.38 Static Jitter
Length
T.38 is an ITU-T standard that VoIP devices use to send fax messages over the
Internet.
Select the number of milliseconds for the jitter buffer size used for transmitting
T.38 fax messages.
Table 68 VoIP > General > Media (continued)
LABEL DESCRIPTION
Table 69 VoIP > General > QoS
LABEL DESCRIPTION
SIP ToS/DiffServ Enter the DSCP value you want to mark on all outgoing SIP packets generated by
the BM2022w for DiffServ-enabled networks. Since DiffServ uses the first 6 bits
of the 8-bit IP ToS field to represent the DSCP value, enter here the 6-bit DSCP
value you want to mark in hexadecimal (in a format of 0x00), and the BM2022w
will then automatically append 2 bits '0' to make a whole 8-bit ToS field value for
all outgoing SIP packets.
For example, if you enter 0x2E, it is 101110 in binary for DSCP. The BM2022w
converts it to 10111000
in binary and marks on the IP ToS field of all the
outgoing SIP packets.
RTP ToS/DiffServ Enter the DSCP value you want to mark on all outgoing VoIP data packets
(including both RTP and T.38 UDPTL packets) generated by the BM2022 for
DiffServ-enabled networks.