The SBC can be configured to operate with up to nine active policy servers for load sharing and/or redundancy in a Centralized PSX routing scenario.
Policy requests are distributed among active PSXs via the round robin process. When an active PSX becomes congested, the SBC applies call-gapping to distribute any overflow traffic to an uncongested active server in the pool, or else to an uncongested standby server. For example, if a PSX becomes congested such that only three out of four transactions get through, then one out of four transactions skip the server and overflow to another server in the 'Active' state.
The SBC promotes a standby PSX to 'Active' status whenever one of the currently-active PSX goes out-of-service or becomes unreachable.
This section provides examples of the steps an administrator uses from CLI and EMA to configure the SBC to communicate with external PSX policy servers in 'Active', 'Standby' or 'Alternate' modes.
The external PSX pool maximum is increased to 40.
CLI:
% set system policyServer localServer PSX_LOCAL_SERVER mode outOfService % show system policyServer localServer PSX_LOCAL_SERVER state disabled; mode outOfService; action dryUp; transactionTimer 2500; keepAliveTimer 5; retryTimer 2500; retries 1;
On SBC main screen, navigate to Configuration > System Setup > Policy Server > Local Server. The Local Server window is displayed.
CLI:
% set system policyServer globalConfig reconnectTimeout 10 switchOverMode automatic congestionControl enabled type mgmt mgmtInterfaceGroup mgmtGroup % show system policyServer globalConfig reconnectTimeout 10; switchOverMode automatic; congestionControl enabled; type mgmt; mgmtInterfaceGroup mgmtGroup
On SBC main screen, navigate to Configuration > System Setup > Policy Server > Global Config. The Global Config window is displayed.
CLI:
% set system policyServer remoteServer PSX1-A ipAddress 10.20.123.12 state enabled mode active % show system policyServer remoteServer PSX1-A ipAddress 10.20.123.12; state enabled; mode active;
On SBC main screen, navigate to Configuration > System Setup > Policy Server > Remote Server. The Remote Server window is displayed.
CLI:
% set system policyServer remoteServer PSX1-B ipAddress 10.20.123.13 state enabled mode standby % show system policyServer remoteServer PSX1-B ipAddress 10.20.123.13; state enabled; mode standby;
On SBC main screen, navigate to Configuration > System Setup > Policy Server > Remote Server. The Remote Server window is displayed.
alternate
".CLI:
% set system policyServer remoteServer PSX2-A ipAddress 10.20.123.14 state enabled mode alternate % show system policyServer remoteServer PSX2-A ipAddress 10.20.123.14; state enabled; mode alternate;
On SBC main screen, navigate to Configuration > System Setup > Policy Server > Remote Server. The Remote Server window is displayed.
For a complete list of commands and parameters, please refer to either the CLI Reference Guide or EMA User Guide.