Use the System window to take an SBC node out of service and to specify how you want to manage any existing call traffic on the node. To optimize the use of resources in cloud environments, you might choose to remove an SBC instance when the call volume is low. The SBC provides options you can configure to minimize the impact on existing calls and registrations by allowing a period of  time for existing calls to "dry up" when you are taking an instance out of service. 

Note:

This feature is not available on M-SBC nodes.

In the SBC, the R-Factor computation is decoupled from QoS Routing. As a result, the SBC computes a call's R-Factor and adds it to the Call Data Records (CDRs) even if the QoS routing is not enabled. The parameter R Factor Computation is added to the Global system level configuration CLI. If enabled, the SBC computes a call's R-Factor and adds it to the STOP CDR.

The R-factor is populated in the STOP CDR in the following fields:

  • Ingress Inbound R-Factor
  • Ingress Outbound R-Factor
  • Egress Inbound R-Factor
  • Egress Outbound R-Factor

From the SBC main screen, navigate to All → Global → System. The System window opens with the System options available for editing.

 

Use the following table to configure the options then click Save.

Table 1: System (Global) Parameters

ParameterDescription
ActionUse this parameter to specify how the SBC handles existing calls when the Mode is set to Out Of Service. The following options are available:
  • Dry Up - (default) When this option is selected, the SBC enters an "Out Of Service Pending" state and rejects any new calls. For existing calls, a timer is started and only terminated after the timer expires. The duration of that timer is determined by the Dry Up Timeout parameter.  During the dry up period, messages involved in the maintenance of existing call legs such as re-INVITEs or UPDATEs are allowed. Out-of-session messages are rejected. Once all the existing calls/registrations/subscriptions are terminated or cleared, or the Dry Up Timeout value expires (whichever happens first), the SBC enters the Out Of Service state.
  • Force - When this option is selected, the SBC immediately enters the Out Of Service state. Any existing calls are terminated immediately and the Dry Up Timeout parameter does not apply.
 
Anonymize DTMF Logging

Enable this flag to anonymize DTMF digits from the TRC file. This is to ensure the DTMF digits don't contain personal information such as credit card and personal identification details. A new file with extension ".TRC.ANN" is generated under the evlog directory, and the original file remains unchanged. If you disable this feature, the copied ".TRC.ANN" files are not deleted in case different log streamers/collectors require them.

File anonymization applies to TRC log level 4 only. This feature does not support anonymizing DTMF data below log level 4.

  • Disabled (default)
  • Enabled

Note: This feature is applicable to SBC SWe on AWS, Azure and GCP (public cloud) environments only.

Dry Up TimeoutThis option specifies the time interval (in minutes) the SBC allows for existing calls to complete before the SBC transitions fully to the Out Of Service state. Once set, you cannot change the value of the running timer unless you change the system back to In Service mode. Changing the value once a dry up action is in progress has no effect on the system. The supported range is 15 minutes to 1440 minutes (1 day). The default is 120 minutes.
Mode

Use this parameter to set the system state. The options are:

  • In Service - (default) When this option is selected, the SBC functions normally and the other options do not apply. The SBC accepts new calls and refreshes existing calls in accordance with standard SBC functionality.
  • Out Of Service - When this option is selected, the SBC rejects any new calls, registrations, or subscriptions. Existing calls are dealt with in accordance with the settings for the Action and Dry Up Timeout parameters.
R Factor Computation

Enable this flag to compute the R-Factor and add it to the STOP CDR even if the QoS routing is not enabled. Since R-Factor computations are CPU-intensive, this parameter limits the computations to applicable call flows only. The default setting is "disabled".

  • Disabled (default)
  • Enabled