AudioCodes E-SBC

CHAPTER21 SIP Message Manipulation
Mediant 1000 Gateway & E-SBC | User's Manual
The device also supports a built-in SIP message normalization feature that can be enabled per
Message Manipulation rule. The normalization feature removes unknown SIP message elements
before forwarding the message. These elements can include SIP headers, SIP header parameters,
and SDP body fields.
The SIP message manipulation feature supports the following:
■ Manipulation on SIP message type (Method, Request/Response, and Response type)
■ Addition of new SIP headers
■ Removal of SIP headers ("black list")
■ Modification of SIP header components such as values, header values (e.g., URI value of the
P-Asserted-Identity header can be copied to the From header), call's parameter values
■ Deletion of SIP body (e.g., if a message body is not supported at the destination network this
body is removed)
■ Translating one SIP response code to another
■ Topology hiding (generally present in SIP headers such as Via, Record Route, Route and
Service-Route).
■ Configurable identity hiding (information related to identity of subscribers, for example, P-
Asserted-Identity, Referred-By, Identity and Identity-Info)
■ Multiple manipulation rules on the same SIP message
■ Apply conditions per rule - the condition can be on parts of the message or call’s parameters
■ Multiple manipulation rules using the same condition. The following figure shows a
configuration example where Rules #1 and #2 ('Row Rule' configured to Use Previous
Condition) use the same condition as configured for Rule #0 ('Row Rule' configured to Use
Current Condition). For more information, see the description of the 'Row Rule' parameter in
this section.
The following figure illustrates an example of a SIP message that is manipulated by the device as
follows:
1. Removes the "Unknown_header: unknown_value" in the incoming message.
2. Changes the P-Asserted-Identity header value to "sip:200@10.33.216.1" in the outgoing
message.
- 510 -