AudioCodes Mediant 500 E-SBC, User Manual

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User's Manual 12. Network
Version 6.8 127 Mediant 500 E-SBC
12.6 Configuring Quality of Service
The QoS Settings page lets you configure Layer-2 and Layer-3 Quality of Service (QoS).
Differentiated Services (DiffServ) is an architecture providing different types or levels of
service for IP traffic. DiffServ (according to RFC 2474), prioritizes certain traffic types
based on priority, accomplishing a higher-level QoS at the expense of other traffic types.
By prioritizing packets, DiffServ routers can minimize transmission delays for time-sensitive
packets such as VoIP packets.
You can assign DiffServ to the following class of services (CoS) and assign VLAN priorities
(IEEE 802.1p) to various values of DiffServ:

Media Premium – RTP packets sent to the LAN

Control Premium – control protocol (SIP) packets sent to the LAN

Gold – HTTP streaming packets sent to the LAN

Bronze – OAMP packets sent to the LAN
The Layer-3 QoS parameters define the values of the DiffServ field in the IP header of the
frames related to a specific service class. The Layer-2 QoS parameters define the values
for the 3 priority bits in the VLAN tag according to the value of the DiffServ field in the
packet IP header (according to the IEEE 802.1p standard). The DiffServ table lets you
configure up to 64 DiffServ-to-VLAN Priority mapping (Layer 2 class of service). For each
packet sent to the LAN, the VLAN Priority of the packet is set according to the DiffServ
value in the IP header of the packet.
The mapping of an application to its CoS and traffic type is shown in the table below:
Table 12-13: Traffic/Network Types and Priority
Application Traffic / Network Types Class-of-Service (Priority)
Debugging interface Management Bronze
Telnet Management Bronze
DHCP
Management Network
Web server (HTTP) Management Bronze
SNMP GET/SET Management Bronze
Web server (HTTPS) Management Bronze
RTP traffic Media Premium media
RTCP traffic Media Premium media
T.38 traffic Media Premium media
SIP Control Premium control
SIP over TLS (SIPS)
Control Premium control
Syslog Management Bronze
SNMP Traps Management Bronze
DNS client
Varies according to DNS settings:

OAMP

Control
Depends on traffic type:

Control: Premium Control

Management: Bronze