SIP Parameter Modification

Table Of Contents

SIP Parameter Modification

Prerequisites

Restrictions

SIP Parameter Modification

The SIP Parameter modificationfeature allow customers to add, remove, or modify the SIP parameters in the SIP messages going out of a border element. The SIP message is generated from the standard signaling stack, but runs the message through a parser which can add, delete or modify specific parameters. This allows interoperability with additional third party devices that require specific SIP message formats. All SIP methods and responses are supported, profiles can be added either in dial-peer level or global level. Basic Regular Expression support would be provided for modification of header values. SDP parameters can also be added, removed or modified.

This feature is applicable only for outgoing SIP messages. Changes to the messages are applied just before they are sent out, and the SIP SPI code does not remember the changes. Because there are no restrictions on the changes that can be applied, users must be careful when configuring this feature - for example, the call might fail if a regular expression to change the To tag value is configured.

The all keyword is used to apply rules on all requests and responses.

Prerequisites

Cisco Unified Border Element

•Cisco IOS Release 12.4(15)XZ or a later release must be installed and running on your Cisco Unified Border Element.

Cisco Unified Border Element (Enterprise)

•Cisco IOS XE Release 2.5 or a later release must be installed and running on your Cisco ASR 1000 Series Router.

Restrictions

•This feature applies to outgoing SIP messages.

•This feature is disabled by default.

•Removal of mandatory headers is not supported.

•This feature allows removal of entire MIME bodies from SIP messages. Addition of MIME bodies is not supported.

SUMMARY STEPS

1. enable

2. configure terminal

3. dial-peer voice number voip

4. voice-class sip profiles group-number

5. response option sip-header option ADD word CR

6. exit

7. end

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	voice service number voip Example: Router(config)# voice service 1 voip	Enters VoIP voice-service configuration mode.
Step 4	voice-class sip-profiles group-number Example: Router(config)# voice-class sip profiles 42	Establishes individual sip profiles defined by a group-number. Valid group-numbers are from 1 to 1000.
Step 5	response option sip-header option ADD word CR Example: Router(config)# request INVITE sip-header supported remove	Add, change, or delete any SIP or SDP header in voice class or sip-profile submode.
Step 6	exit Example: Router(config-dial-peer)# exit	Exits the current mode.
Step 7	end Example: Router(config-voi-srv)# end	Returns to privileged EXEC mode.

Example

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voice service voip

allow-connections sip to sip

redirect ip2ip

sip

early-offer forced

midcall-signaling passthru

sip-profiles 1

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voice class sip-profiles 1

request INVITE sip-header Supported remove

request INVITE sip-header Min-SE remove

request INVITE sip-header Session-Expires remove

request INVITE sip-header Unsupported modify "Unsupported:" "timer"

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