Via

An example of the header is shown below:

Via: SIP/2.0/UDP 10.132.10.128;branch=z9hG4bKUGOKMQPAVFKTAVYDQPTB

The header properties are shown in the following table:

Header Level Action	Add	Delete	Modify	List Entries
Operations Supported	No	No	No	10

Keyword	Sub Types	Attributes
Alias	Boolean	Read Only
Branch	String	Read Only
Host	Host Structure (see Host)	Read Only
MAddrIp	gnTIPAddress	Read Only
Param	Param	Read/Write
Port	Integer	Read Only
TransportType	Enum TransportType (see TransportType)	Read Only

Below is a header manipulation example:

Rule:	Check the transport type in the first Via header and if it's set to UDP, then modify the From header's URL: ■ Message Type: Invite.request ■ Condition: header.VIA.0.transporttype == '0' ■ Action Subject: header.from.url ■ Action Type: Modify ■ Action Value: 'sip:3200@110.18.5.41;tusunami=0'
Result:	From: <sip:3200@110.18.5.41;user=phone;tusunami=0>;tag=1c7874