Steering Pools
Steering pools define sets of ports that are used for steering media flows through the Oracle Communications Session Border Controller. These selected ports are used to modify the SDP to cause receiving session agents to direct their media toward this system. Media can be sent along the best quality path using these addresses and ports instead of traversing the shortest path or the BGP-4 path.
For example, when the Oracle Communications Session Border Controller is communicating with a SIP device in a specific realm defined by a steering pool, it uses the IP address and port number from the steering pool’s range of ports to direct the media. The port the Oracle Communications Session Border Controller chooses to use is identified in the SDP part of the message.
Note:
The values entered in the steering pool are used when the system provides NAT, PAT, and VLAN translation.Configuration Overview
To plan steering pool ranges, take into account the total sessions available on the box, determine how many ports these sessions will use per media stream, and assign that number of ports to all of the steering pools on your Oracle Communications Session Border Controller. For example, if your Oracle Communications Session Border Controller can accommodate 500 sessions and each session typically uses 2 ports, you would assign 1000 ports to each steering pool. This strategy provides for a maximum number of ports for potential use, without using extra resources on ports your Oracle Communications Session Border Controller will never use.
- IP address—IP address of the steering pool.
- start port—Port number that begins the range of ports available to the steering pool. You must define this port to enable the system to perform media steering and NAT operations.
- end port—Port number that ends the range of ports available to the steering pool. You must define this port to enable the system to perform media steering and NAT operations.
- realm id—Identifies the steering pool’s realm. The steering pool is restricted to only the flows that originate from this realm.
Note:
The combination of entries for IP address, start port, and realm ID must be unique in each steering pool. You cannot use the same values for multiple steering pools.Each bidirectional media stream in a session uses two steering ports, one in each realm (with the exception of audio/video calls that consume four ports). You can configure the start and end port values to provide admission control. If all of the ports in all of the steering pools defined for a given realm are in use, no additional flows/sessions can be established to/from the realm of the steering pool.