Selector Rules

Selector Rules

Selector Rules are used in various configuration contexts to define rules for selecting a value for a parameter based on a list of rules.

Rules are matched based on selectors to fields in the InitialDP (e.g. MSC address), derived from it (e.g. normalised calling party), or configured tags. Each rule must provide a value, either as a literal or copied from an InitialDP, derived, or tag field. All selectors in a rule must match in order for the rule to be selected. If no selectors are present (e.g. only a literal is configured), the rule will always match, acting as a catch-all.

Rules are traversed in order, and the first matching rule found will have its value extracted.

Note that, depending on the source network and the InitialDP → eventTypeBCSM, some fields may not be available for selection. In such cases, rules using these fields will assume no value is present.

An example configuration extract might be:

      <config>
        <diameter>
          <request>
              <service_identifiers>
                <rule eventTypeBCSM="3" serviceKey="1" bearerCap_itc="0" literal="201"/>
                <rule serviceKey="1" bearerCap_itc="0" literal="201"/>
                <rule serviceKey="1" literal="201"/>
                <rule serviceKey="2" literal="202"/>
                <rule bearerCap_itc="8" literal="301"/>
                <rule callingPartysCategory_hex="8" literal="401"/>
                <rule location="roaming" literal="402" />
                <rule literal="501"/>
              </service_identifiers>
              <rating_groups>
                <rule service_key="1" literal="2"/>
                <rule literal="2"/>
              </rating_groups>
              <requested_times>
                <rule literal="60"/>
              </requested_times>

The service_identifier rules here will attempt to assign a Diameter Service-Identifier based on the service key, bearer capability, calling party category, or derived location, with a fallback value if no deeper match occurs. The rating_group rules will check service key only, with a fallback value used otherwise. All InitialDP messages rececived will always use 60 as the Diameter Requested-Service-Unit.CC-Time value from the fallback rule.

Match Inversion

Some fields in selector rules may have their match be made inverted. To do this, add the character ! to the start of the match value.

If the string to be matched starts with an exclamation mark, add an additional !, i.e. !! for a normal match and !!! for an inverted match.

Some examples of using and not using inversion:

• rule specifies abc (match only abc):
  • against actual value abc: match
  • against actual value abd: no match
  • against actual value !abc: no match
  • against actual value !abd: no match
• rule specifies !abc (match anything that is not abc):
  • against actual value abc: no match
  • against actual value abd: match
  • against actual value !abc: match
  • against actual value !abd: match
• rule specifies !!abc (match only !abc):
  • against actual value abc: no match
  • against actual value abd: no match
  • against actual value !abc: match
  • against actual value !abd: no match
• rule specifies !!!abc (match anything that is not !abc):
  • against actual value abc: match
  • against actual value abd: match
  • against actual value !abc: no match
  • against actual value !abd: match

Refer to the specific field information for details of which fields can have their match inverted.

Configuration Details

Each rule object for IDP selection can support the following attributes:

Available Fields

Literal Special Cases

For requested time rules, the literal value none may be specified to send a Requested-Service-Unit AVP without any child AVPs.

Initial DP Fields

The following fields sourced from the IDP are available as parameter names for action rule selectors and for value extraction when using the idp source type parameter.

Note that the idp is added by default if it is not already present for the key namespace.

Dynamic Fields

The following fields are managed automatically by the system as a result of data received or actions performed.

CUG Fields

The following fields sourced from the most recent CUG query (if any) are available as parameter names for action rule selectors and for value extraction when using the idp source type parameter: