User Manual

Setting Up Your System
79
from other lower priority traffic. VoIP can guarantee high-quality QoS only if the voice and the
SIP packets are given priority over other kinds of network traffic. Skype for Business phones
support the DiffServ model of QoS.
Voice QoS
In order to make VoIP transmissions intelligible to receivers, voice packets should not be
dropped, excessively delayed, or made to suffer varying delay. DiffServ model can guarantee
high-quality voice transmission when the voice packets are configured to a higher DSCP value.
SIP QoS
SIP protocol is used for creating, modifying and terminating two-party or multi-party sessions.
To ensure good voice quality, SIP packets emanated from Skype for Business phones should be
configured with a high transmission priority.
DSCPs for voice and SIP packets can be specified respectively.
Note
Procedure
QoS can be configured using the configuration files or locally.
Configuration File
<y0000000000xx>.cfg
Configure the DSCPs for voice
packets and SIP packets.
Parameters:
network.qos.rtptos
network.qos.signaltos
Local
Web User Interface
Configure the DSCPs for voice
packets and SIP packets.
Navigate to:
http://<phoneIPAddress>/serv
let?p=network-adv&q=load
Details of Configuration Parameters:
Parameters
Permitted Values
Default
network.qos.rtptos
Integer from 0 to 63
46
Description:
For voice and SIP packets, the Skype for Business phone obtains DSCP info from the network
policy if LLDP feature is enabled, which takes precedence over manual settings. For more
information on LLDP, refer to LLDP on page 55.