QoS Based Routing

In addition to configuring your system for routing based on certain session constraints, you can also set up routing based on QoS. QoS based routing uses the R-Factor on a per-realm basis to either cut back on the traffic allowed by a specific realm, or to shut that traffic off altogether.

To use this feature, you set up QoS constraints configurations and apply one per realm. The QoS constraints configuration allows you to set up two thresholds:

• Major—The major threshold sets the R-Factor limit beyond which the Oracle® Enterprise Session Border Controller rejects a certain percentage (that you configure) of calls. That is to say, it rejects inbound calls at the rate you set with a 503 Service Unavailable status code, and rejects outbound calls if there are no alternative routes.
• Critical—The critical threshold, when exceeded, causes the Oracle® Enterprise Session Border Controller to behave the same way it does when any of the session constraints (set in the session-constraints configuration) are exceeded. All inbound calls to the realm are rejected with a 503 Service Unavailable status code, and (if there is no alternate route) outbound calls are rejected, too. Until the R-Factor falls within acceptable means and the session constraint’s time-to-resume value has elapsed, the realm remains in this state.