Policy-Based Routing Application Example - Avaya G430 Manual

Policy-based routing

Policy-based routing application example

The following example creates a policy-based routing scheme in which:
• Voice traffic is routed over an external Serial interface using an external Layer 3 router
connected to the gateway. If the interface is down, the traffic is dropped.
• Data traffic is routed over a GRE tunnel. If the tunnel is down, the traffic is routed over
the external Serial interface. If both interfaces are down, the traffic is dropped.
The following figure illustrates the sample application described below.
This example includes a voice VLAN (6) and a data VLAN (5). The PMI is on VLAN 6. The
Branch Gateway is managed by a remote Media Gateway Controller (MGC) with the IP address
149.49.43.210. The Branch Gateway also includes a local S8300 in LSP mode.
IP phones are located on the same subnet as the PMI. Therefore, there is no routing between
the PMI and the IP phones.
In this example, the object of policy-based routing is to route all voice traffic over the E1/T1
line, which is more expensive but provides the superior QoS necessary for voice traffic.
Remaining traffic is to be routed over the more inexpensive Internet connection.
It is assumed that the IP phones on VLAN 6 establish connections with other IP phones on the
same subnet, sending signalling packets to the MGC, and bearer packets directly to other IP
phones or to the Branch Gateway.
The policy-based routing configuring starts with PBR list 801. This list requires all voice packets
addressed to the MGC (149.49.43.210) with DSCP values that indicate voice transmission (34,
41, 43, 44, and 46) to be routed according to next hop list 1. This list directs packets to the T1/
E1 interface. If that interface is down, the packets are dropped.
598 Administering Avaya G430 Branch Gateway
Comments? infodev@avaya.com
October 2013