Administration of the Avaya G350 Media Gateway - Avaya Support

Chapter 19: Configuring policy-based routingThis chapter provides information about configuring policy-based routing on the G350 andcontains the following sections:●●●●●●●●Policy-based routing overview — an overview of policy-based routingApplications — a description of common policy-based routing applicationsConfiguring Policy-Based Routing — instructions on how to configure policy-based routingPBR Rules — instructions on how to configure rulesNext Hop Lists — instructions on how to configure next hop listsEditing and Deleting PBR lists — instructions on how to modify and delete PBR listsDisplaying PBR lists — instructions on how to view the configuration of PBR listsApplication example — an example of a policy-based routing applicationPolicy-based routing overviewPolicy-based routing allows you to configure a routing scheme based on traffic’s source IPaddress, destination IP address, IP protocol, and other characteristics. You can usepolicy-based routing (PBR) lists to determine the routing of packets that match the rules definedin the list. Each PBR list includes a set of rules, and each rule includes a next hop list. Each nexthop list contains up to 20 next hop destinations to which the G350 sends packets that match therule. A destination can be either an IP address or an interface.Policy-based routing takes place only when the packet enters the interface, not when it leaves.Policy-based routing takes place after the packet is processed by the Ingress Access ControlList and the Ingress QoS list. Thus, the PBR list evaluates the packet after the packet’s DSCPfield has been modified by the Ingress QoS List. See Figure 23: Applying Policy Lists toPackets on page 258.Note: TheNote:Note:Loopback 1 interface is an exception to this rule. On the Loopback 1interface, PBR lists are applied when the packet leaves the interface. Thisenables the PBR list to handle packets sent by the G350 device itself, asexplained below.Note:Extended keepalive provides the interface with the ability to determine whether anext hop is or is not available. See Extended keepalive on page 99.Issue 3 January 2005 273