Loop Sensing for PSTN Calls

When the Oracle Enterprise Communications Broker (Communications Broker) routing table contains no explicit route to the agent, the Communications Broker routing engine uses an implicit route that assumes the Communications Broker is directly available to the agent. Depending on your routing needs, you might choose to configure a default route to handle calls not routed by the implicit routes. For some calls, the default route will result in a loop back to the previous hop. Such looping can cause undesirable traffic in the network and result in calls that never reach the end point. To prevent call looping, use the next-hop-policy-condition parameter to construct a policy for the default route that prevents the Communications Broker from sending a call back to the previous hop.

Using the next-hop-policy-condition in a policy, in combination with a skip action, removes the default route as a choice for some calls and prevents the Communications Broker from forwarding a call:

back to the agent that sent the call.
to a group of agents when the agent that sent the call is a member of the group.
back to the agent when the IP address matches the host in the from-uri of the received message.
to a group of agents when any agent in the group uses an IP address and port that matches the host in the from-uri of the received message.

The next-hop-policy-condition compares the next hop in the route to either the previous hop or the from-uri-host. When either previous hop or from-uri-host resolves to true, the Communications Broker executes the deny action to stop call looping.

The process for configuring call loop prevention requires the following steps:

Set the next-hop-policy-condition in a policy, along with the comparison type and the deny action.
Add the policy to the target route.