AudioCodes MP-26 series, User Manual

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User's Manual 11. Quality of Service
Version 4.4.0 143 MP26x/MP27x
11.3 Configuring Traffic Priority
Traffic Priority allows you to manage and avoid traffic congestion by defining inbound and
outbound priority rules for each device on your gateway. These rules determine the priority
assigned to packets traveling through the device. QoS parameters (DSCP marking and
packet priority) are set per packet, on an application basis.
You can set QoS parameters using flexible rules, according to the following parameters:

Source/destination IP address, MAC address or host name

Device

Source/destination ports

Limit the rule to
specific days and hours
The device supports two priority marking methods for packet prioritization:

DSCP

802.1p Priority
The matching of packets by rules is connection-based, known as Stateful Packet
Inspection (SPI), using the same connection-tracking mechanism used by the
firewall.
Once a packet matches a rule, all subsequent packets with the same attributes receive the
same QoS parameters, both inbound and outbound.
A packet can match more than one rule, and therefore:

The first class rule has precedence over all other class rules (scanning is stopped
once the first rule is reached).

The first traffic-priority (classless) rule has precedence over all other traffic-priority
rules.

There is no prevention of a traffic-priority rule conflicting with a class rule. In this case,
the priority and DSCP setting of the class rule (if given) takes precedence.
Connection-based QoS also allows inheriting QoS parameters by some of the applications
that open subsequent connections. For instance, you can define QoS rules on SIP and the
rules then apply to both control and data ports (even if the data ports are unknown). This
feature applies to all applications that have ALG at firewall:

Any

User Defined (FTP, HTTP, HTTPS, TFTP, IMAP, PING, POP3, SMTP, Telnet, L2TP,
Traceroute or any other protocol)