Using Regular Expression Adaptations, you can build your own adaptations to define criteria and instructions for message modification that use regular expressions.

You can also define rules based on multiple conditions in the content of SIP messages. You can define conditions on R-URI, Response-Line, standard and custom SIP Headers, and attachment bodies.

Each regular expression adaptation has up to two lists of one or more adaptation rules, where one list is for ingress adaptation and the other for egress adaptations.

You can define the order of adaptation rules. Each adaptation rule consists of one condition, zero or more variables, and a list of one or more ordered actions.

If the condition is not assigned to the adaptation rule, the rule executes unconditionally.

The action can be to add, modify, or delete the header, request, response line, or the attachment of an identified message.

When Session Manager processes a message, Session Manager applies ingress and/or egress adaptation rules in the administered order. The egress adaptation rules are executed in the order the rules are administered. The adaptation rule checks whether the message matches the defined condition. If the condition matches, the values of administered variables are determined and set, and administered actions are executed to adapt the message.

Ingress rules are based on regular expression adaptations associated with the SIP entity sending the message and Egress rules are based on regular expression adaptations associated with the destination SIP entity of the message.