Sip Message Manipulation; Configuring Sip Message Manipulation - AudioCodes Mediant 4000 SBC User Manual

CHAPTER 21 SIP Message Manipulation
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SIP Message Manipulation

This section describes SIP message manipulation.

Configuring SIP Message Manipulation

The Message Manipulations table lets you configure up to 500 Message Manipulation rules. A
Message Manipulation rule defines a manipulation sequence for SIP messages. SIP message
manipulation enables the normalization of SIP messaging fields between communicating network
segments. For example, it allows service providers to design their own policies on the SIP
messaging fields that must be present before a SIP call enters their network. Similarly, enterprises
and small businesses may have policies for the information that can enter or leave their networks
for policy or security reasons from a service provider. SIP message manipulations can also be
implemented to resolve incompatibilities between SIP devices inside the enterprise network.
Each Message Manipulation rule is configured with a Manipulation Set ID. You can create groups
(sets) of Message Manipulation rules by assigning each of the relevant Message Manipulation rules
to the same Manipulation Set ID. The Manipulation Set ID is then used to assign the rules to
specific calls:
■ Message manipulation rules can be applied pre- or post-classification:
● Pre-classification Process: Message manipulation can be done on incoming SIP dialog-
initiating messages (e.g., INVITE) prior to the classification process. You configure this by
assigning the Manipulation Set ID to the SIP Interface on which the call is received (see
Configuring SIP
● Post-classification Process: Message manipulation can be done on inbound and/or
outbound SIP messages after the call has been successfully classified. Manipulation
occurs only after the routing process - inbound message manipulation is done first, then
outbound number manipulation (see
then outbound message manipulation. For viewing the call processing flow, see
Processing of SIP Dialog
ID to the relevant IP Group in the IP Groups table (see
■ SIP requests initiated by the device: You can apply Message Manipulation rules to SIP
requests that are initiated by the device, for example, SIP REGISTERs for certain entities
(e.g., Accounts) and keep-alive by SIP OPTIONS. If the destination of the request is an IP
Group, then the device uses the Inbound and Outbound Manipulation Sets that are assigned to
the IP Group. If there is no IP Group for the destination or the IP Group is not assigned an
Inbound or Outbound Manipulation Set, then the global parameters
GWInboundManipulationSet or GWOutboundManipulationSet are used. The
GWInboundManipulationSet parameter defines the Message Manipulation Set that is applied
to incoming responses for requests that the device initiated. The GWOutboundManipulationSet
parameter defines the Message Manipulation Set that is applied to outgoing requests that the
device initiates.
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
Interfaces).
Configuring IP-to-IP Outbound
Requests. You configure this by assigning the Manipulation Set
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Manipulations), and
Configuring IP Groups).
Call