AudioCodes Mediant 500 MSBR, User Manual

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Version 7.2 381 Mediant 500 MSBR
User's Manual 22. SIP Message Manipulation
22 SIP Message Manipulation
This section describes SIP message manipulation.
22.1 Configuring SIP Message Manipulation
The Message Manipulations table lets you configure up to 102 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:

SBC application: 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 Interfaces on page 325).
•
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 Configuring
IP-to-IP Outbound Manipulations on page 705), and then outbound message
manipulation. For viewing the call processing flow, see Call Processing of SIP
Dialog Requests on page 631. You configure this by assigning the Manipulation
Set ID to the relevant IP Group in the IP Groups table (see Configuring IP Groups
on page 333).

Gateway application: Message Manipulation rules are applied to calls as follows:
•
Manipulating Inbound SIP INVITE Messages: Message manipulation can be
applied only to all inbound calls (not specific calls). This is done by assigning a
Manipulation Set ID to the "global" ini file parameter,
GWInboundManipulationSet.
•
Manipulating Outbound SIP INVITE Messages:
a. Message manipulation can be done for specific calls, by assigning a
Manipulation Set ID to an IP Group in the IP Groups table, using the
'Outbound Message Manipulation Set' parameter.
b. Message manipulation can be applied to all outbound calls (except for IP
Groups that have been assigned a Manipulation Set ID). This is done by
assigning a Manipulation Set ID to the "global" ini file parameter,
GWOutboundManipulationSet.
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: