1. Configuration Guide
  2. STIR/SHAKEN Client
  3. Mapping SIP to HTTP Headers and Parameters

Mapping SIP to HTTP Headers and Parameters

You can configure the SBC with static mapping of signaling information to and from SIP INVITEs and HTTP requests or responses. This mapping provides a means of conveying SIP header and parameter information within HTTP headers and vice-versa. The HTTP exchanges can be during authentication and verification procedures. This feature applies to both ATIS and 3GPP modes.

This feature performs the following functions:

  • Adds headers and their new parameters to the rules' targets
  • Modifies existing headers with the new parameters presented by the rule

You configure this feature using the sti-header-mapping-ruleset in the session-router. From this parameter, you create multi-instance sub-elements that contain your SIP/HTTP mapping rules. You then assign rulesets to:

  • sti-server
  • sti-config

The ruleset assigned to a sti-server takes precedence over the sti-config configuration.

The SBC uses these rulesets to perform actions when presented with STIR/SHAKEN flows, including:

  • Selecting the source-header and/or source-parameter you specify with configuration
  • Adding any new header into the target content
  • Adding or modifying the selected parameter to the target content
  • Adding or modifying the selected parameter to a target-header

For each SIP call that invokes STIR/SHAKEN authentication or verification, the SBC first checks the applicable sti-server for a configured sti-header-mapping-ruleset-name. If found, the SBC uses the corresponding ruleset to get the mapping details. If it is not found, the SBC checks for an applicable configuration in the sti-config for the same purpose.

You configure a ruleset by specifying:
  • The ruleset identifier
  • The headers and/or parameters the system uses as the source for the mapping
  • The headers and/or parameters the system uses as the target for the mapping
  • The role, STI-AS or STI-VS, within which the ruleset operates
  • The direction of the mapping, based on the perspective of the SBC

For call flows that include a single HTTP request and response, the SBC behaviors are the same for both ATIS and 3GPP modes. In 3GPP mode when there are both SHAKEN and DIV signing request/responses, the SBC:

  • Adds the mapped data to both the SHAKEN and DIV signing request towards the STI-AS.
  • Uses the following behaviors when receiving responses for both SHAKEN and DIV signing requests:
    • If it receives multiple responses, the SBC processes and saves the first response. When it receives the second, the SBC processes this second response but does not save it. This results in any final processing using the first response.
    • If the same header for which mapping is set is present in both responses, the SBC have either value from the response that will be processed later that overwrites value from the response that was processed first, or headers that would be duplicated (if [^] or [~] is used in the mapping-rule).

Header and Parameter Mapping Statistics

The SBC provides a command to show statistics on traffic for which is has performed header modification. To see these statistics, run the show stir header-mapping.