Session Manager introduces a new Variable construct.

Using the Variable, you can write regular expression that identifies a part of SIP message and store the value in the newly-defined Variable. You can use the same Variable to adapt other parts of the message.

The regular expression based adaptation module uses the variable construct.

Variables that are administered for regular expression adaptation rule evaluated for every message that matches the condition of a rule. The set of variables for one message cannot be used in another message.

If the regular expression matches the at least part of the source string, the variable is assigned the value of the first capture group and the subsequent capture groups are ignored. The variable is not assigned if there is no capture group in the regular expression.