Qos Lists; Policy-Based Routing - Avaya G250 Administration

QoS lists

You can use QoS lists to change the DSCP and Ethernet IEEE 802.1p CoS fields in packets.
Changing these fields adjusts the priority of packets meeting the criteria of the QoS list. DSCP
values are mapped to a CoS value. Rules can be created determining the priority behavior of
either individual DSCP values or CoS values, and can be based on specific values or groups of
IP addresses, protocols, ports, IP fragments, or DSCP values. When a packet matches a rule
on the QoS list, the G250/G350 sets one or both of the QoS fields in the packet. The following
table shows these QoS fields:
Each QoS list also includes a DSCP table. The DSCP table enables you to set one or both of
the QoS fields in a packet based on the previous value of the DSCP field in the packet.
QoS lists have the following parts:
Rule list — a list of filtering rules and actions for the G250/G350 to take when a packet
●
matches the rule. Match actions on this list are pointers to the composite operation table.
Actions (composite operation table) — a table that describes actions to be performed
●
when a packet matches a rule. The table includes pre-defined actions such as permit and
deny. You can configure more complex rules. Refer to
DSCP map — a table that contains DSCP code points and match action pairs. Match
●
actions are pointers to the composite operation table. Refer to

Policy-based routing

You can use policy-based routing to determine the routing path a packet takes based on the
type of packet or the packet's source or destination IP addresses or DSCP field. This enables
you to route different types of traffic over different routes or interfaces. For example, you use
policy-based routing to route voice traffic over a WAN interface and data traffic over the Internet.
Policy-based routing is implemented by means of policy-based routing (PBR) lists. PBR lists are
similar in many respects to access control lists and QoS lists. However, since there are also
some key differences, policy-based routing is explained in a separate chapter. Refer to
Configuring policy-based routing
Layer
2
3
on page 553.
QoS field
802.1p
DSCP
Allowed values
0–7
0–63
Composite operations
DSCP table
Issue 3 February 2007
on page 545.
on page 548.
533