How to use the “SIP header” component in wolkvox Studio
Written by Jhon Bairon Figueroa
Updated at September 29th, 2026
Table of Contents
Introduction
The SIP header component in wolkvox Studio allows additional information to be included within the SIP signaling of a call. It is located in the Advanced component group and is available only for Voice Flow Routing Points.
This component can be used to transport application information through the SIP User-to-User header, also known as UUI (User-to-User Information). UUI makes it possible to send a small block of data along with the establishment of a SIP session, without this information being part of the signaling required to control the call.
Its purpose is to facilitate the exchange of metadata between the systems involved in a communication. For example, an application can include information related to the customer, the reason for the contact, or a business identifier so that another system can receive and use it during call processing.
How to use the SIP header component
To use this component, open the Voice Flow Routing Point that you want to configure in wolkvox Studio.
- In the components panel, select the “Advanced” category.
- Locate the SIP header component.
- Drag the component onto the Voice Flow canvas and place it at the point in the process where you need to add the information to the SIP header. Double-click the component with the left mouse button to open its configuration panel.
- Configure the fields:
- Under “Select item”, select the header you want to use. To transport UUI information, select User-to-User.
- In the “Value” field, enter the information that will be sent within the header.
- Click “Save” to store the configuration.
What is User-to-User?
User-to-User Information (UUI) is a mechanism used to transport additional information between applications during the establishment of a SIP session.
This information is transmitted through the following header: User-to-User
The content of the header is independent of the basic signaling used to establish or control the call. Its meaning is defined by the applications that generate and receive the information.
For example, a UUI value could have a structure such as: 56a390f3d2b7310023a2;encoding=hex;purpose=foo;content=bar
In this example, 56a390f3d2b7310023a2 corresponds to the transported data, while the parameters separated by semicolons make it possible to add information about how it should be interpreted.
The exact format that must be entered in Value will depend on the integration and on what the destination system expects to receive.
What can it be used for?
The SIP header component can be especially useful when wolkvox needs to exchange additional information with other applications or telephony systems during a call.
| Use case | Example |
|---|---|
| Customer identification | Send a customer identifier so another application can recognize the customer when receiving the call. |
| Interaction context | Transport information related to the reason for contact or to a previous process completed in an IVR. |
| CRM integrations | Send identifiers that make it possible to associate the call with a customer, case, opportunity, or another record. |
| Call transfers | Preserve relevant information when the call continues to another system or application configured to receive the header. |
| Business logic | Transport codes or data that another system can use to determine how to process the call. |
Important considerations
The SIP header component is designed to transport application metadata and not to control basic call functions.
Information sent through User-to-User will only be useful if the receiving system is configured to recognize and interpret the received content. For this reason, the value format must be defined according to the existing integration between the systems.
In addition, the amount of information that can be transported through this type of header is limited, so it is recommended to use short data, identifiers, or values required to complement the call context rather than large volumes of information.